338 AMl'HIPODA NOIIMALIA. 



shorter than hasos : of tliird pair half narrower, Rubolliptical, ante- 

 rior margin about apex serrate ; remaining joints a little longer 

 than hasos : of fifth pair obliquely sublanceolato, apex truncate ; 

 next joint small and nearly round. 

 " Length 4 lines. 





" Ifah. Atlantic, in latitude 4° 25' S., longitude 21° 30' W. Col- 

 lected November 7, 1838." — Dana. 



) 



8. LYC^A. 

 Lycaja, Dana, U. S. Exjjlor. Uxju'd. p. 1017. 

 " Pigments of the eyes large. Inferior antenna) folded up beneath 

 the ccphalon on either side, and having the liagellum long. Gna- 

 thopoda [complexly] subchcliform. Pereiopoda of moderate length, 

 last two pairs abbreviated ; basa of three posterior pairs rather 

 narrow. Pleon not folding against the venter." — Dana. 



This genus closely resembles Pronoe, differing from it only in the 

 character of the gnathopoda. It appears to me that the suggestion 

 of Dana (op. cit. p. 98G) bears quite as strongly on this genus, in 

 relation to Pronoe, as it does on Metoechus in relation to Hyperia. 

 I think it probable that research may ultimately show that some of 

 the preceding genera (^Thamyris, Ampliipronoe, Pronoe, and Dyca'a) 

 are unnecessary ; but since I have not seen specimens of the last 

 two, I feel bound to accept their authors' definition. 



1. Lycasa ochracea. (Plate LIII. fig. 8.) 

 Lycsea ochracea, Dana, U. S. Explui: Dx2)cd. p. 1017. pi. G9. f. 6. 



** Ccphalon nearly round, Pereion distinctly seven-jointed. Infe- 

 rior pair of antenna.' naked; fu'st joint short; second and third 

 long and equal ; fourth very small, not oblong ; the following part 

 slender and flexible, about as long as the third joint. Pleon with 

 a triangular and obtuse extremity. Poda all naked. First pair of 

 g-nathopoda broad, hardly oblong, inferior apex triangular : second 

 pair of gnathopoda a little oblong, narrower than the fii'st, sub- 

 rectangular. First and second pairs of pereiopoda slender ; third 

 pair longer than fourth ; fifth weak, coxa more than twice as long 

 as the following part ; basa of the three posterior pairs of pereio- 

 poda subequal. 



" Length 4 lines. 



" Hab. Pacific, near Sunday Island, north of New Zealand. Col- 

 lected April 1840, from the ca^dtics of Salpa\" — Dana. 



