178 bulletin: museum of comparative zoology. 



The other segments strongly striate, the striae running obHquely 

 ventrocaudad and the two uppermost ones in the middle region of 

 the body leaving a mid-dorsal triangular area on each somite with 

 apex, which is anterior, a little truncate, each stria taking its origin 

 on the front margin a little ectad of the median sulcus; striae not 

 extending so high on first few segments while in the most caudal ones 

 they meet at the middle, forming two or more triangles one outside 

 the other. 



Tubercles of anal scutum prominent, their setae long. 



Number of segments, forty-four. 



Length, near 27 mm.; depth, 2.8 mm.; width, 2.5 mm. 



77a. Stemmiulus insulanus, sp. nov. 



Typc.— M. C. Z. 4,321. Trinidad: near Port of Spain. Roland 

 Thaxter. Paratype~M. C. Z. 4,322 Trinidad: near Port of Spain. 

 H. L. Clark. 



In this species the head and the first three segments are light 

 ferruginous without distinct darker markings. The following part 

 of the body is abruptly darker. There is a very narrow mid-dorsal 

 light line. Each average somite has the anterior half blackish, the 

 posterior brownish of a pronounced purplish tinge, these two regions 

 being separated by a narrow pale stripe which extends from the mid- 

 dorsal stripe to the pale ventral region and expands in its course so 

 as to produce two small dots of which there are thus two series. Legs 

 yellow. Antennae dark. Last dorsal plate and anal valves ferrugi- 

 nous like the anterior region. 



The body has the usual subfusiform shape but is especially strongly 

 narrowed caudad. 



Ocellus large, dark, strongly convex, situated immediately caudad 

 of the antenna] socket. 



The collum is widely convex in front. The lower end is rounded, 

 not truly angulate. Lower part crossed above margin by two sharp 

 sulci below each of which the plate is ridged somewhat keel-like, with 

 the posterior ends of these projecting as teeth or serrations. 



Anal scutum caudally rounded, mesally emarginate, with the usual 

 six setigerous cones additional to the median process. Anal valves a 

 little exceeding the scutum. 



x\nterior gonopods of male excavated distally on the mesal side, 

 strongly uncate, the apical region of each curving mesad and then 



