154 C.ONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



JASSIM:. 



Interantennal lobes often somewhat prominent. Fourth coxal 

 plates usually not excavate behind. 



Accessory flagellum of first antennae never large, often indis- 

 tinct. 



Third joint of mandibular palp shorter than second, laminar. 



Gnathopods subchelate, second pair larger than first, often 

 greatly modified in the male. First and second pereiopods glandu- 

 lar; third pair reverted; fifth pair the longest. 



Third uropods with very short rami of which the outer is 

 uncinate and usually surmounted by denticles. Telson simple. 



Jassa Leach. 



Fourth coxal plates not perceptibly emarginate behind. 



Antennae setose, with flagellum shorter than elongated pedun- 

 cle. First antennae with first joint of peduncle shorter tjian 

 second or third ; accessory flagellum very small. Second antenna 

 usually considerably larger than first. 



Mandibles with large palp having third joint shorter than 

 second, distally widened, and densely setose. First maxillae with 

 inner plate very small and provided with marginal setae; second 

 joint of palp long. 



Second gnathopods much larger than first, stronger in male 

 than female; hind margin of propodus of male produced into 

 a strong tooth. First and second pereiopods glandular with 

 basal joint slightly expanded. Posterior pereiopods with basal 

 joint somewhat expanded. 



First and second uropods with outer ramus shorter than 

 inner. Third uropods with stout peduncle much longer than 

 rami, the outer one of which ends in a hooked spine. Telson 

 triangular. 



Jassa marmorata Holmes. 



1903. Jassa marmorata , Holmes, Amer. Naturalist, vol. 37, 

 p. 289. 



1905. Jassa marmorata, Holmes, Bull. U. S. Bur. Fish., vol. 

 24, p. 511. 



Head produced into a small, broadly triangular rostrum. 

 Body moderately depressed. First two coxal plates as deep as 



