Cyrtognatha nigrovittata Keyserling, 1881

Dimitrov, Dimitar & Hormiga, Gustavo, 2009, Revision And Cladistic Analysis Of The Orbweaving Spider Genus Cyrtognatha Keyserling, 1881 (Araneae, Tetragnathidae), Bulletin of the American Museum of Natural History 2009 (317), pp. 1-140 : 98-115

Cyrtognatha nigrovittata Keyserling, 1881 Figures 62, 63

Cyrtognatha nigrovittata Keyserling, 1881: 276 , pl. 11, fig. 5.

TYPE: Male holotype from Peru, Pumamarca. No date information on the label, K. Jelski and J. Sztolcman ( MIZ 132 ; examined)

DIAGNOSIS: Cyrtognatha nigrovittata is diagnosed by the presence of a short clawshaped apophysis on the metine embolic apophysis (fig. 62A, D). The membrane surrounding the distal part of the embolus (fig. 62A, B, D) is also very characteristic and different from all other Cyrtognatha species. The elongated abdomen with very long and longitudinally oriented distal tubercle is an additional diagnostic character that allows easy identification.

DESCRIPTION: Male (holotype). Habitus as in figures 62E, 63A–C. Carapace brownish with a well-marked fovea and darker median band. Legs brownish, darker than the cephalothorax. Abdomen cylindrical with brownish color and few remains of guanine spots. Proximal tubercles of the abdomen very small. Distal tubercle very large, conical, with the tip oriented caudally. The tubercle itself is almost as long as one-third of the abdomen (fig. 63B, C). Total length 7.80. Cephalothorax 2.41 long, 1.30 wide, 0.93 high. Abdomen 5.39 long, 0.93 wide, 0.93 high. Sternum yellowish with edges slightly darker with brownish pigmentation; 1.05 long, 0.93 wide. Endites and labium darker with brown pigmentation. Clypeus height 1.6 times one AME diameter. All eyes surround- ed by darker pigmentation and nearly the same size. AME diameter 0.08. Distance between AME slightly larger than their diameter. Distance between AME and ALE 1.5 AME diameters. Distance between PLE equal to their diameter. ALE and PLE close to each other, placed over short elevations. Chelicerae (fig. 62E) widely divergent and darker than the rest of the cephalothorax. Dorsal cheliceral tooth very well developed and outlying the fang articulation. Cheliceral fang with a small outgrowth. Femur I 5.64, 2.3 times the length of the cephalothorax. Pedipalp as in figure 62A–D. Palpal tibia length 0.28; cymbium length 0.97.

Female. Unknown.

DISTRIBUTION: Known only from the type locality (fig. 5).

NOMEN DUBIUM

Cyrtognatha aproducta Franganillo, 1926 was originally described from Cuba. This species was omitted in Roewer’s (1955) catalog, but it is included in Platnick’s (2006) catalog with a small note about Roewer’s decision. Franganillo’s (1926) description does not provide diagnostic drawings and by itself is not sufficient to identify this species. Unfortunately, the collection of Pelegrín Franganillo has suffered serious damage through the years. It is currently deposited at the Instituto de Ecología y Sistemática in La Habana ( Cuba) where recent examinations ( Huber and Pérez González, 1998) found that many of the specimens are lost and the remaining material is not readily accessible because the vials lack labels. Huber and Pérez González (1998) noted that although the vials are numbered, the collection catalog has been lost so that the numbering does not provide any useful information.

Considering the current state of the Franganillo’s collection and the insufficient information given in the original description, we consider Cyrtognatha aproducta to be a nomen dubium.

MISPLACED SPECIES

Genus Tetragnatha Latreille, 1804 Tetragnatha lactensis ( Mello-Leitão, 1947) , new combination Figure 64

Agriognatha lactensis Mello-Leitão, 1947: 11 , fig. 25

TYPE: Female holotype from Brazil, Minas Gerais, Carmo do Rio Claro , Jose C. M. Carvalho ( MNRJ 1826 ; examined) .

TRANSFER JUSTIFICATION: In the original description ( Mello-Leitão, 1947) this specimen was placed in the genus Agriognatha without mentioning the most important female structure—the vulva—in Tetragnathinae , species that lack an epigynum. Detailed study of the internal female genitalia revealed a bizarre morphology (fig. 64A, C, D), which does not exhibit the diagnostic characters of Cyrtognatha . Despite being so unusual, this morphology presents some characters com- mon to all Tetragnatha species (e.g., small fingerlike posterior sac and spermathecae). Furthermore, the eye sizes and distribution, as well as the shape of the epigastric furrow (fig. 64B), are as in Tetragnatha . Unfortunately, the male of this species remains unknown and there is only one female specimen available for study; thus, many important characters could not be examined. This complicates the decision about its correct placement; however, based on all the available evidence we consider it a member of the genus Tetragnatha .

DIAGNOSIS: This species can be easily distinguished from all known Tetragnatha by the very unusual shape of the spermathecae. Here the copulatory ducts are nearly straight and the spermathecae consist of a widened channel that is very tangled (fig. 64A, C, D) and narrows slightly toward its end.

DESCRIPTION: Male. Unknown.

Female (holotype). Carapace brownish, with dark brown pigmentation surrounding the eyes. Fovea well marked and placed roughly in the center of the thoracic region. Abdomen elongated with conical shape and brownish coloration. Distal edge of abdomen with darker markings dorsolaterally. Only very few guanine crystals remain (difficult to observe). Legs brown-yellowish. Femur of the fourth leg with short nonfeathered dorsal trichobothria. Total length 8.30. Cephalothorax 2.29 long, 1.55 wide, 1.05 high. Abdomen 6.01 long, 1.55 wide, 1.79 high. Sternum yellowish with darker margins; longer than wide; 1.17 long, 0.68 wide. Endites yellowish, rectangular, and wider distally. Labium slightingly darker than the sternum, trapezoidal, with swollen distal edge. Clypeus height 0.7 times one AME diameter. AME diameter 0.11. Eyes placed in two procurved

rows; first row more procurve, second row nearly straight. PME larger than the other eyes. PLE and AME nearly the same diameter. ALE smallest (at about half of the PME diameter). Distance between AME 1.5 AME diameters; AME–ALE distance at about twice the AME diameter. AME–PME distance nearly the same as the distance between AME. PME slightly more separated than the AME. ALE and PLE close to each other but not juxtaposed; distance between ALE and PLE about 1.2 times one ALE diameter. Chelicerae yellowish, not divergent and without dorsal tooth. Femur I 4.96, 2.3 times the length of the cephalothorax. Vulva as in figure 64A, C, D. Epigastric furrow as in figure 64B.

DISTRIBUTION: Known only from the type locality in Minas Gerais ( Brazil).

Tetragnatha exilima ( Mello-Leitão, 1943) , new combination Figure 65

Cyrtognatha exilima Mello-Leitão, 1943: 176 . Cyrtognatha exilima Brignoli, 1983: 221 .

TYPE: Female holotype in Brazil, Rio Grande do Sul, P. Ramos ( MNRJ 41757 ; examined)

TRANSFER JUSTIFICATION: After examining the type specimen we consider the placement of this species in Cyrtognatha to be incorrect, as it lacks any of the diagnostic characters of this genus (e.g., PLS macrosetae, feathered trichobothria of femur IV, touching PLE, reduction of the spermathecae). It has the eye pattern, genital morphology (fig. 65A, B), and shape of the endites and labium (fig. 65E) as in Tetragnatha , and therefore it is transferred to the latter genus.

DIAGNOSIS: The shape of the spermathecae and the morphology and placement of the uterus externus (fig. 65A) are diagnostic. Although the spermathecae in this specimen are not completely chitinized, they can be easily observed and allow clear distinction of this species from other congeners.

DESCRIPTION: Male. Unknown.

Female (holotype). Habitus as in figure 65B–E. Carapace brown-yellowish, elongated, and centrally with a well-marked fovea. Cephalothorax width very uniform except for the slightly narrower cephalic region. Abdomen cylindrical, very long with numerous guanine spots dorsally. The guanine spots extend over the upper half of the lateral sides of the abdomen. The remains of the lateral surface of the abdomen and its ventral part lack guanine crystals and exhibit a darker brownish pigmentation. Total length 6.84. Cephalothorax 1.57 long, 0.75 wide, 0.50 high. Abdomen 5.27 long, 0.75 wide, 0.75 high. Sternum yellowish, longer than wide, 0.87 long, 0.50 wide. Endites divergent and wider distally. Labium with swollen distal edge. Clypeus height 3.4 times one AME diameter. AME diameter 0.06. Eyes in two procurved rows. Anterior eyes smaller than the posterior. ALE smallest and placed close to the PLE. Distance between AME 2.5 times one AME diameter; AME– ALE distance 1.5 times one AME diameter. PLE and PME nearly the same size. Distance between PME equal to their diameter; PLE– PME distance about 1.5 PLE diameters. All eyes are surrounded by an area with dark brown pigmentation. Chelicerae (fig. 65B) yellowish with seven anterior and two posterior teeth. One of the anterior teeth away from the other six almost in the middle of the distal margin of the chelicerae. The other six close to each other, placed on the retrolateral margin and with gradually increasing size distally. Femur I 4.96, 3.1 times the length of the cephalothorax. Vulva as in figure 65A.

DISTRIBUTION: Known only from the type locality in Rio Grande do Sul ( Brazil).

Genus Glenognatha Simon, 1887 Glenognatha globosa ( Petrunkevitch, 1925) , new combination Figure 66

Cyrtognatha globosa Petrunkevitch, 1925: 123 , fig. 42.

TYPE: Female holotype from Panama, San Lorenzo. 4.xii.1924, A. and W. Petrunkevitch (most likely subadult), holotype ( YPM; examined) .

TRANSFER JUSTIFICATION: Detailed study of the holotype of this species showed that it has all of the diagnostic characters of the genus Glenognatha . The chelicerae are shaped as in Glenognatha , and the cheliceral teeth are also as in this genus (fig. 66D, E). The abdomen is globular and does not have a distal tubercle, while in Cyrtognatha it is oval to cylindrical and usually has a distal

(E), lateral (F). Female chelicerae frontal (D). Scale bars 0.5 mm.

tubercle. Femur IV lacks the feathered trichobothria that occur in Cyrtognatha . The single most important character suggesting the placement of this specimen in Glenognatha is the advanced tracheal spiracle, a unique characteristic of Glenognatha and one of the most robust autapomorphies of this genus. Based on all these findings we consider that the transfer of this species to Glenognatha is fully justified.

DIAGNOSIS: The specimen depicted in figure 66A, B is most probably a subadult female, and thus the spermathecae are not completely formed. However, the morphology of the uterus externus and the median membranous chamber of the vulva (fig. 66A,B) are very different from those observed in other Glenognatha species. The presence of a series of widened rings on the chamber connecting with the uterus externus (fig. 66A, B) is unique to this species.

DESCRIPTION: Male. Unknown.

Female (holotype). Habitus as in figure 66C–F. Carapace yellow-brownish with a well-marked fovea. Cephalic region elevat- ed with easily distinguishable cephalic junction. Abdomen spherical with remains of distinctive marking dorsally and darker band ventrally (this specimen is very depigmented and it is impossible to say what its coloration pattern is when alive). Total length 3.99. Cephalothorax 1.62 long, 1.25 wide, 1.00 high. Abdomen 2.37 long, 2.12 wide, 1.75 high. Sternum yellowish, slightly darker than the rest of the cephalothorax; 0.75 long, 0.80 wide. Endites slightly wider distally and almost parallel. Labium trapezoidal, elongat- ed, and with darker basal part. Clypeus height 1.7 times one AME diameter. AME diameter 0.12. Eyes in two rows, anterior row procurved, posterior row almost straight. Lateral eyes smaller and very close to each other (touching in their bases). Median eyes grouped close together frontally. AME slightingly smaller than PME. Distance between AME half of their diameter; AME–ALE distance twice one AME diameter. Distance between PME equal to their diameter and between them and PLE 1.5 PLE diameters. All eyes surrounded by a darker pigmentation. Chelicerae (fig. 66D) robust, narrower proximally, and with two rows (one anterior and one posterior) of strong teeth distally. Each row has eight teeth Fig. 73. Continued.

Fig. 76.

increasing in size toward the fang. Dorsal tooth present, well developed, and outlying the fang articulation. Femur I 2.75, 1.7 times the length of the cephalothorax. Vulva as in figure 66A, B.

DISTRIBUTION: Known only from the type locality in Panama.