HICIIKR CRUSTACEA OF NIAV YORK CI'rY 



175 



46 Sphaeroma quadridenta- 



Leng-th 8 mm. l)rcaclth 4 mm. 

 Color very \-arial)lc, some slaty 

 g'ray or marked on the back with 

 a whitish, cream-colored or rosa- 

 ceous long'itiidinal patch bor- 

 dered more or less with black. 

 The color is evidently protective, 

 as it matches closely the rocks on 

 which the animals are found. 



Taken at Bartow. Another 

 smaller species, as yet unde- 

 scribed, and apparently belonging 



to this genus, has been found tum (After Harder) 



swimming around in the small pools left by the tide, at City Island 



and on Staten Island. 



3 VALVIFERA 



Uropoda ventral, arching over and protecting the pleopoda, which 



are delicate and mostly branchial in character. 



Of the three families one is represented. 



Family idoteidae 

 Antennulae of four segments, the basal segment enlarged and 

 the terminal one clavate. 



Pleon with more or fewer of its seg- 

 ments consolidated into a scutiform tail- 

 piece. 



Idotea marina (Linn.) 



O 11 i s c u s m a r i 11 n s Finnaeiis. Fauna 

 Suecica. 1761. p. 500. 



Stenosoma irrorata DeKay. /. c. 

 1844. p.43, pi. 10, fig.42. 



Idotea irrorata Verrill. /. c. 1874. 

 p.569, pi. 5, rig.23. Flarger. /. c. 1880. p.343, 

 pi. 5, fig.24-26. 



Idotea marina Richardson. /. c. 1901. 

 P-540. 



Body with sides nearly parallel. 

 Antennulae short, of four segments. 

 Hfrfery ^ ^ o t ea ma r i n a (After Antennae lougcr, with multiarticulatc 



