Arvechamboides, Shelley, Rowland M., 2007

Shelley, Rowland M., 2007, Arvechamboides ocala, n. gen., n. sp., a new aniulinine milliped from peninsular Florida, USA (Julida: Parajulidae), Zootaxa 1440, pp. 61-68 : 62-63

Arvechamboides , new genus

Type species. A. ocala , new species.

Diagnosis. A genus of moderately-long, relatively narrow Aniulini with sternum of pleurotergite 8 narrow, extending dorsad well into body cavity and expanding laterad into broad lobes. Anterior gonopods (ag) dominated by broad sternum extending medially into strong, apically bilobed, triangular projection; coxal lobes, lateral syncoxal processes, and dorsal "shelves" absent; telopodites elongate, not clavate. Posterior gonopod (pg) with three projections -- a prefemoral process, accessory prefemoral process, and telopodite; prefemoral process arising basally on medial surface of prefemur, curving anterioventrad caudal to telopodite and terminating near midlength of latter; accessory prefemoral process arising distad on lateral surface of prefemur, directed ventrad within curvature arc of telopodite; latter long and slender, curving broadly anteriad and overhanging accessory prefemoral process.

Distribution. Northcentral peninsular Florida ( Fig. 1 ).

Species. Only one is known.

Remarks. The pgs of Arvechamboides possess three projections that arise from the prefemur, the telopodite (Fig. 10, PT) being the longest and carrying the prostatic groove. Each of the two shorter projections could thus be labeled "prefemoral process," but anatomical terms must be applied consistently throughout a taxon and only to homologous structures. The prefemoral processes in Aniulus , Aniulus (Hakiulus) , Gyniulus , Oriulus , and Pseudojulus arise basally from the medial surface of the prefemur and extend distad generally somewhat caudal to the telopodite ( Hoffman 1992; Shelley 2000 a, b, 2001 b, 2002, 2004); only in Arvechambus does this projection arise distally on the prefemur and extend directly ventrad so as to lie "inside" the curvature arc of the telopodite ( Causey 1963, Shelley 2004). The two shorter prefemoral projections in Arvechamboides arise at these same positions, indicating homologies with the respective branches in the other taxa; I therefore restrict the term "prefemoral process" (Fig. 10, PFP) to the more common, basal branch and employ "accessory prefemoral process" (Fig. 10, APFP) for the distal structure that occurs only in Arvechambus and Arvechamboides . A third pg branch, labeled process "C," occurs in Nesoressa Shelley & Medrano, 2006 (tribe Nesoressini), but its different relative position on the pg and the fundamentally different gonopodal structure are not indicative of homology ( Shelley & Medrano 2006). The distal configuration of the prefemoral process in Arvechamboides resembles that of the pg telopodite in Aniulus (Hakiulus) amophor Chamberlin, 1940 (see Shelley 2000 b, fig. 27), but this similarity seems insignificant.

While it exhibits traits of both Pseudojulus and Arvechambus , Arvechamboides shares more features with the latter; the only ones shared with Pseudojulus are possession of the prefemoral process and elongated sterna on pleurotergite 8. The following table summarizes differences between Arvechamboides and Arvechambus , both of which lack dorsal "shelves" and lateral syncoxal processes on the ags and possess elongate, non-clavate ag telopodites.

Arvechamboides is the fourth parajulid genus recorded from Florida, all in the Aniulini, and the second known only from the state, the other being Gyniulus . Because of its presence in Clay and Bay cos. ( Shelley 2000 a, 2001), some 30–60 mi (48–96 km) south of the closest points in Georgia & Alabama, Gyniulus conceivably occurs in these states; however, as the sole locality of Arvechamboides , in Marion Co., is around 100 mi (160 km) from the border with Georgia, it may truly be endemic to Florida. Known occurrences of Floridian parajulid genera are compared in fig. 1.

Arvechamboides Arvechambus

Body relatively long and slender. Body large and robust, stout.

Sternum of pleurotergite 8 long & slender, extending dor- Sternum of pleurotergite 8 short & relatively broad, sad well into body cavity. extending only moderately dorsad into body cavity. Anterior gonopods without coxal lobes. Anterior gonopods with prominent coxal lobes. Anterior gonopod sternum broad and prominent, extending Anterior gonopod sternum small, rounded, and inconspicumediad into subtriangular projection. ous, without medial lobe or projection.

Posterior gonopod with prefemoral process, accessory Posterior gonopod with accessory prefemoral process and prefemoral process, and telopodite. telopodite.

Posterior gonopod telopodite long and narrow, curving Posterior gonopod telopodite short, broad, and truncated, anteriad and overhanging & extending beyond level of extending directly ventrad and not curving anteriad, termiaccessory prefemoral process. nating at level of inner margin of accessory prefemoral process except in A. weemsi , in which latter leans caudad.

Figures

FIGURE 1. Occurrences of parajulid and aniulinine genera in Florida. Dots, Gyniulus; Triangles, Pseudojulus; Stars, Arvechambus; Star in dot, Arvechamboides.