MILLIPEDS — ^HOFFMAN 213 



caudally bordered by the greatly elevated sternal area of the 7th 

 legpau". 



Coxae of gonopods rather massive, somewhat longer than the 

 telopodites, the coxal apophysis large but not elevated, its margin 

 nearly smooth. Prefemur of telopodite large, 70 percent of the 

 length, densely setose, prefemoral process slender and bisinuate, poorly 

 sclerotized. Tibiotarsus short and stout, constricted at its midlength, 

 distally expanded and subdeltoid. Secondary tibiotarsus shorter than 

 primary, nearly straight, terminally directed mesiad and slightly 

 hooked, the subterminal process large, perpendicular to the main axis, 

 and directed laterad. 



Female: Similar to the male in external structure, aside from a 

 slightly more arched dorsum. The pleural lobes of the 3d segment 

 are very pronounced and conspicuous. Cyphopods large, the valves 

 in lateral aspect being nearly as large as the mesial face of the recep- 

 tacle. Latter strongly concave on its inner distal surface, and pro- 

 vided there with a small cluster of prominent rounded tubercules and 

 rugosities. Inner valve slightly shorter than outer. 



Color: The color in life is not known, but recently preserved spec- 

 imens are light bro^vn or tan, with the caudolateral halves of the 

 paranota dilute yellow. 



Variation: The three known specimens, a male and two females, 

 measure 71, 72, and 73 mm. in length, respectively. The male 

 appears to be slightly broader in proportion to its length, being 15.5 

 mm. wide in contrast to 14.3 and 14.5 mm. for the females. The 

 latter are entirely similar m details of the cyphopods. 



Distribution : Known so far only from central Alabama, at the 

 edge of the Piedmont. Specimens from slightly to the east, in Tal- 

 ladega County, Ala. (2.7 miles north of Sylacauga, 3 cf cf, May 5, 

 1954, L. Hubricht; and 1 mile east of Renfro, d^ and 9, May 7, 1954, 

 Hubricht), appear to be intermediate in gonopod structure between 

 hubrichti and retrorsus, and are so indicated on the map. These five 

 specimens are very massive; the largest male, 78 mm. long and 16 

 mm. wide, is the largest North American polydesmoid thus far 

 recorded. 



Pachydesmus crassiciitis retrorsus Chamberlin 



Figures 1,c, I0,b, 11,6 



Pachydesmus retrorsus Chamberlin, 1921, p. 232, figs. 3, 4. — Chamberlin and 

 Hofifman, 1958, p. 44. 



Type specimen: Male (MCZ), from Knoxville, Knox County, 

 Tenn., collected by C. N. Ainslie. 



Diagnosis: A very large subspecies of the laticollis phratry, char- 

 acterized particularly by the rather long and slender primary tibio- 



