io6 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY. 



[Bull. 



Fig. 25. Dikerogammarus fasciatus. 



1899. Dikerogammarus fasciatus, Stebbing, Trans. Linn. Soc. 

 London, ser. 2, vol. 7, p. 428. 



Fourth and fifth segments of abdomen slightly raised to a 

 tubercle dorsally and each armed with three fascicles of spines; 

 sixth segment also with three fascicles. 



First antennas with first and second joints of peduncle nearly 

 equal in length and twice as long as the third; flagellum twice 

 as long as peduncle; accessory fiagellum five- or six- jointed. 

 Second antennae setose, about two-thirds the length of the first; 

 last two joints of peduncle subequal. 



First gnathopods in male with propodus much narrowed 

 distally and with palm very oblique, with several small prehensile 

 spines and a stout spine at middle. In the female, the propodus 

 is less narrowed distally and palm is less oblique. Second gnatho- 

 pods in male with carpus longer than in first gnathopods ; pro- 

 podus with margins nearly parallel, but widening slightly toward 

 the palm which is a little oblique and concave and bears a stout 

 spine near the middle. In the female the carpus is proportionally 

 longer and as wide as the propodus which is narrow and 

 rectangular. 



