NO. 1170. TEE FAMILY GOMPHODESMIDM— COOK. 695 



of the flagellum, as in many of the other genera; the base of the fla- 

 gellum beyond the nodus is rather stout, and is then widened, flattened, 

 and excavate, tlie Hattened portion extending laterad; beyond this 

 the leg terminates in an evenly curved and gradually narrowed spine, 

 directed in general upward, with its apex lying under the carina of the 

 sixth segment. 



The (;opulatory legs of the type of this genus are very remarkable 

 and readily distinguish it from all others; instead of being turned 

 mesad beyond the nodus, the tlagella nearly touch the bulbous base of 

 the second joint and are then bent abruptly laterad, expanded and 

 hollowed out into a somewhat spoon-shaped structure, which seems to 

 be continuous with the seminal duct of the spiniform terminal portion. 

 No such expansion or cavity occurs in the other genera. Its existence 

 is probably indicative of some biologic i)eculiarity in the i)reseiit genus. 

 Perhaps the cavity in the exi)anded i)ortiou of the copulatory leg 

 accommodates the seminal fluid, which it would not in that case be 

 necessary to carry down to the reservoir of the basal joint. 



The specimen which has served mainly for the above description pre- 

 sents a hitherto unknown abnormality in that the eleventh segment 

 has a pore on one side and none on the other. The distribution of the 

 pores in the present order is, as far as any recorded observations are 

 concerned, absolutely constant in the same species, but the ])resent 

 instance shows that such variation is not impossible, and should accord- 

 ingly be sought for the more carefully as furnishing evidence on the 

 systematic value of tlie i)ore formula. 



NEODESMUS JUVENIS, new species. 



(Plate LVI, tigs. 3a-3c.) 



Eurydesmua moasamhiciis Peters, Reise NjkIi Mossainbl(|u*', Zoologie, 1862, V, 

 p. .533, ])ro i)arte, i. c, the auimals supposed by Peters to be youug. 



Vertex without hairs, not strongly convex, distinctly rugulose ; sulcus 

 distinct below, obsolete above; suture distinct, 



Clypeus not hirsute, rather flat; a pair of setiferous (?) punctations 

 near together near the lower end of the sulcus of the vertex; two iiairs 

 of similar punctations much wider apart between these and the labral 

 edge; lateral edges of labrum slightly emarginate, the lower corners 

 rather square. 



First segment subreniform by reason of the broad posterior emargi- 

 nation; the lateral carime are somewhat evenly rounded, the posterior 

 corner being nearly obsolete; submarginal ridge somewhat more pro- 

 nounced than in ISphenodesmiis riufulosus, broadest at the posterior cor- 

 ner and gradually narrowed into the anterior raised margin; posterior 

 raised margin very short. 



Segments densely and flnely rugulose over their entire surface. 



Lateral carinaj rather narrow, inserted about halfway up; marginal 

 callus distinct and moderately prominent, not greatly broadened on 



