HIGHER CRUSTACEA OF NEW YORK CITY 



175 



Fig. 46 Sphaeroma quadridenta- 

 t u m (After Harder) 



Length 8 mm, breadth 4 mm. 

 Color very variable, some slaty 

 gray or marked on the back with 

 a whitish, cream-colored or rosa- 

 ceous longitudinal patch bor- 

 dered more or less w r ith 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 

 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 IIJOTEIOAE: 



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 n i s c u s m a r i n n s Linnaeus. Fauna 

 Suecica. 1761. p. 500. 



Stenosoma i r r o r a t a DeKay. /. c. 

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



Idotea irrorata Verrill. /. c. 1874. 

 9.569, pi. 5, fig.23. Harger. /. c. 1880. p-343, 

 pi. 5, ng.24-26. 



Idotea marina Richardson. /. c. 1901. 

 P-540. 



Body with sides nearly parallel. 

 Antennulae short, of four segments. 

 T d l ea ma r in a < After Antennae longer, with multiarticulate 



