218 bulletin: museum of comparative zoology. 



cate to its base into two slender, distally acute processes of which 

 the caudal one is weakly bent toward the tip and the anterior one, 

 which contains the seminal duct, bent more strongly mesocaudad 

 toward the tip. /w situ these principal, distally geniculate, processes 

 cross in the middle line. 

 Length, 16 mm. 



161. DocoDESMUS PARViOR, sp. nov. 



Type.— M. C. Z. 4,471. Haiti: Furcy. W. M. Mann. 



This is a very much smaller form than D. haitiensis above described 

 and it is also much darker brown, color nearly uniform. The keels 

 but little lighter than the mid-dorsum. The number of crenulations on 

 the lateral margins of the keels is as in that species; but the emargina- 

 tions between the crenuli are deeper and more acute. The border of 

 the head is more abruptly concavely depressed contiguously to the 

 elevated median region and the free edge is more elevated. Lateral 

 tubercles of anal tergite small, the latter not appearing trilobate. 

 The caudolateral processes of the penult somite projecting a little 

 mesad of caudad, thus a little converging, narrowly rounded at tip. 



Length about 8.5 mm.; width, 2 mm. 



162. DoCODESMUS GRENADAE, sp. nOV. 



Type.— M. C. Z. 4,482. Parafypes.— M. C. Z. 4,472, 4,473. 

 Grenada: Grand Etang. Roland Thaxter. 



This species is a much darker brown than D. haitiensis and lacks the 

 median dorsal light stripe, the keels also maintaining the same dark 

 color. 



A smaller species than D. haitiensis but with similar relative pro- 

 portions. The keels in general slightly bent forwards in the middle 

 region, with the anterior margins straight while the posterior margins 

 are slightly convex. The crenations on the posterior margins of the 

 keels much more pronounced than in D. haitiensis, the emarginations 

 deep. Crenations on lateral margins also stronger but the emargina- 

 tions not so deep as those of the caudal margin. In the last tergite 

 the median lobe decidedly smaller in comparison with the lateral 

 lobes or tubercles than in D. haitiensis, more rounded. 



In the male gonopods the basal lobes are smaller than in D. haitiensis 



