HIGHER CRUSTACEA OF NEW YORK CITY 



177 



Another species, Idotea metallica Bosc, (I. robusta 

 of Yerrill and Harger) will probably be taken. It may be distin- 

 guished by the truncate terminal abdominal segment. 



Edotea triloba (Say) 



Idotea triloba Say, T. Acad. Nat. Sci. Phila. Jour. 1818. 1 1425. 

 Epelys trilobus Verrill. /. r. 1874. p.57i. Harger. /. c. 1880. 



p. 358, pi. 7, iig-42-43- 



Edotea t r i 1 o 1) a Richardson. /. f. 190 r. p. 545- 



Body flat, elongated in form 

 and the lateral edges of the seg- 

 ments smoothly rounded. A de- 

 pressed line runs from the pos- 

 terior lateral angles of the head 

 across all the segments to the 

 pleon. Pleon consisting of a 

 single piece pointed at the end. 

 Antennulae and antennae short. 



Length 6 mm, breadth 2.3 

 mm. Color uniform, dull. 



Found under stones or creep- 

 ing over the bottoms or amidst 

 and beneath the decaying vege- 

 table matter in sheltered situations. 



Taken on eastern shore of Staten Island. 



4 ASELLOTA 



Segments of pleon fused into a shieldlike plate. Pleopoda ex- 

 clusively branchial and reduced in number. Uropoda terminal as in 

 Chelifera and biramous. Antennulae small, antennae sometimes 

 very large. Five families, two represented. 



Family ASELLIDAE, 



Mainly fresh-water forms, distinguished by the pleopoda, which 

 number in the female four pairs, the first very small and not oper- 

 culiform, the rest biramous, the second pair forming an operculum 

 for the last two. In the male there are five pairs, an additional 

 pair, the copulatory appendages, being interposed between the first 

 and second pairs. 



Fig. 49 Edotea t r i 1 o ba (After Harger) 



