Mimuloria dilatata, Hennen & Shelley, 2015

Hennen, Derek A. & Shelley, Rowland M., 2015, A contribution on the milliped tribe Nannariini (Polydesmida: Xystodesmidae): Revalidation of Mimuloria Chamberlin 1928; identities of Fontaria oblonga C. L. Koch 1847, and Nannaria minor Chamberlin 1918; elucidation of the tribal range; and commentaries on Nannaria Chamberlin 1918, and Oenomaea Hoffman 1964, Insecta Mundi 2015 (418), pp. 1-21 : 14-15

Mimuloria dilatata , new species

Diagnosis. Acropodite curving gently mediad, ornamentation a variably rounded lobe or swelling; prefemoral process extending for 3/4 or more of acropodital length, terminating outside of arc and directed away from stem, with variable basal lobe.

Etymology. The specific name references the apical dilation on the outer/anterior acropodital surface.

Distribution. Occurring in Tennessee from the western Cumberland Plateau to the Ridge and Valley Province and spanning the Tennessee River.

M imuloria dilatata dilatata , new status Fig. 18–19 .

? Fontaria tennesseensis (not Bollman, 1889b): Chamberlin 1918b: 28.

Type specimens. Male holotype ( FSCA) and one male and two female paratypes ( FSCA, NCSM), collected by R. M. Shelley, 9 May 1979, in the campground of Henry Horton State Park, Marshall Co., Tennessee.

Diagnosis. Acropodital lobe an indistinct, poorly defined swelling; prefemoral process sublinear or curving gently mediad distally, terminating well below level of acropodital tip, basal lobe small, rounded.

Holotype. Length unmeasurable, maximum width ~ 4.1 mm.

Somatic features agreeing closely with those of M. castanea with following exceptions. Width across genal apices 3.2 mm. Facial setae as follows: epicranial, interantennal, subantennal, frontal, and genal 0–0, clypeal about 5–5, labral about 12–12, merging with clypeal series and continuing for short distances along genal borders. Antennae reaching back to caudal margin of 3 rd tergite; relative lengths of antennomeres 3>4=5>2=6>1>7. Anterior and caudolateral corners of 2 nd – 4 th paranota rounded, caudolateral corners of 5 th paranota slightly extended, becoming progressively more so on caudal paranota. Sternal spines present on segments 8–18. Relative lengths of postgonopodal podomeres 3>6>4>2>5>1. Coxae through tibiae sparsely hirsute, tarsi with slightly denser hairs; prefemoral spines short, overhanging at most 1/4 – 1/3 of femoral lengths. Tarsal claws spatulate on legs 4–7, broad on legs 9–12.

Gonopod structure ( Fig. 18–19 ) as follows: Prefemoral process extending for approximately ¾ of acropodital length, angling away from stem and tapering smoothly and continuously to subacuminate tip, curving gently mediad distally and terminating well below level of acropodital tip, basal lobe small and rounded, located mediad. Acropodite bowing gently mediad, not overhanging tip of prefemoral process, tapering smoothly and continuously distad but expanding into subapical swelling on outer/ anterior margin then angling ventromediad and tapering to narrowly rounded tip; inner margin with narrow, linear lamina opposite swelling.

Male paratype. The male paratype agrees closely with the holotype.

Variation. The basal lobe on the prefemoral process is smaller in the Davidson Co. male, and the distal curve is fainter, though the structure still angles away from the acropodital arc. The subapical acropodital swelling is also smaller.

Distribution. Known from central and southcentral Tennessee along the highway I-65 corridor south of I- 440 in Nashville, in the Nashville Basin and western Cumberland Plateau physiographic provinces.

Published record. Tennessee: Davidson Co., “Glendale Hills” (generally south of Nashville but precise location unknown) ( Chamberlin 1918b).

Additional record. Tennessee: Davidson Co., Nashville, “Glendale Hills,” 2M, June 1917, H. Cummins (NMNH).

Remarks. Two adults and two immatures of “ Fontaria tennesseensis ” Bollman 1889b , now in Nannaria ( Chamberlin and Hoffman 1958, Hoffman 1999, Marek et al. 2014), were taken at “Glendale Hills” on 21 April 1917 by Harold Cummins ( Chamberlin 1918b), but its type and only authentic locality is Jefferson City (formerly Mossy Creek), Jefferson Co., in the Ridge and Valley province ca. 291.2 km (182.0 mi) to the east. Sexes are not provided and the sample is lost, but the adults were surely unidentifiable females that Chamberlin assigned to F. tennesseensis because it was the most proximate species at the time. We now assign this record to M. d. dilatata , and the fact that Chamberlin did not propose a new species is evidence that the adults were indeed females. With his proclivity for naming and describing ostensible new species, Chamberlin was unlikely to pass up the opportunity to do so with this sample if it had included a mature male. Of course, he also based many names on unidentifiable females, but for some reason did not do so with this sample.

Besides F. tennesseensis, Chamberlin (1918b) reported seven additional millipeds from both “Glendale Hills” and “beyond Glendale” and even described two species from the former. All were collected between 14 October 1916 and 6 May 1917 by Mr. Cummins, an anatomy instructor at Vanderbilt University who later earned a Ph. D. from Tulane and became an anatomy professor in its medical school ( Holt 1976). As the above males were taken a month later, Cummins probably sent them to Chamberlin even later because, again, he would have described a new species if he had had them earlier. Perhaps Chamberlin asked Cummins to revisit the site and search for a male because he did return and found two. Cummins must have sent them to Chamberlin because the sample is at the NMNH, which contains his former holdings, and it is hard to envision it being there otherwise. Whatever the reason, Chamberlin never described this new species, so we do so now,

Figures

Figures 18–23. The dilatata group. 18–19) M. d. dilatata holotype. 18) Telopodite of left gonopod, ventral view. 19) Distal extremity of acropodite, medial view. 20–21) M. d. sigmoidea holotype. 20) Telopodite of left gonopod, ventral view. 21) Basal flange/shoulder of prefemoral process, medial view. 22–23) M. rhysodesmoides holotype. 22) Telopodite of left gonopod, ventral view. 23) Distal extremity of acropodite, submedial view. a, acropodite; pfp, prefemoral process.