THE CRUSTACEA OE NEW JERSEY. 255 



edge. Anterior lateral angles of head pronounced, formed in 

 rounded lobes and containing eyes. First antennae with first and 

 second segments equal in length, third segment twice length of 

 second and fourth segment, about two-thirds length of third. 

 First antenn?e longer than second antennae, latter only reaching 

 to middle of fourth segment of first pair. First antennae with 

 short and subequal first, second and third segments, fourth seg- 

 ment one and one-half longer than third, and fifth segment a 

 trifle longer than fourth. Flagellum minute, formed of one 

 segment one-third length of fifth segment of first antennae. Re- 

 tracted first antennas reach only to middle of lateral edge of first 

 thoracic segment. Maxillipeds with palp of three segments. 

 Third and fourth thoracic segments longer than any others, also 

 broadest. Epimera of all segments united with segments. Lat- 

 eral parts of segments laterally expanded, lateral edges almost 

 straight. Two longitudinal rows of low tubercles, as a series 

 along either side on lateral portions of segments, with two tuber- 

 cles to each segment, one on each side. Abdomen formed of 

 one segment, with suture lines at base to indicate another partly 

 coalesced segment, and also slight incisions in lateral edges. 

 Large rounded prominence in median line at base of abdomen, 

 followed by a depression, so that as seen laterally abdomen 

 formed of two elevations separated by a deep depression, and 

 extremity also separated off from second elevation bv another 

 depression. Sides of abdomen converge rapidly from point little 

 below middle to narrow pointed end. Color uniform, dull. 

 Length 7 mm. 



Remarks. — Originally described from Egg Harbor, it has been 

 found to the north in Maine. It lives in eel-grass, on piles, in 

 sand and in tide-pools. It is essentially a surface species, living 

 in low muddy water, apparently not below one-half fathom in 

 depth. I have examined Say's type, of which only half remains, 

 and that dried and pinned. 



Genus IDOTEA Fabricius. 



Idotea Fabricius, Siippl. Entomol. Syst., 1798, p. 302. Type Cymothoa emar- 



ginata Fabricius, fifth species. 

 Idothea Fabricius, 1. c, Index Alpb., 1799, p. 27. Type Cymothoa enutrginata 



Fabricius, fifth species. 



