MARINE ISOPODA OF NEW ENGLAND, ETC. 



429 



The following nineteen have been found only north of Cape Cod: 



Gyge Hippolytes. 

 Phryxns abdominalis. 

 Dajus mysidis. 

 Janira alta. 

 Janira spinosa. 

 Munna Fabricii. 

 Munnopsis typica. 

 Burycope robusta. 

 Synidotea nodulosa. 



Astacilla granulata. 

 Cirolana polita. 

 uiEga psora. 

 Sysceniis infelix. 

 Gnathia cerina. 

 Leptochelia limicola. 

 Leptochelia rapax. 

 Leptochelia filum. 

 Leptochelia coeca. 



Synidotea bicuspida. 



The remaining sixteen are included in the following list as found on 

 both sides of Cape Cod, but the letter n. is used to designate such species 

 as are common north and rare south of the Cape, and s. signifies that the 

 species is common at the south but rare northwards. 



Philoscia vittata, s. 

 Jaera albifrons. 

 Ilyarachna species.* 

 Chiridotea coeca. 

 Chiridotea Tuftsii, N. 

 Idotea irrorata. 

 Idotea phosphorea, N. 

 Idotea robusta. 



Epelys trilobus, s. 

 Epelys montosus, N. 

 Sphaeroma quadridentatum, s. 

 Limnoria lignorum. 

 Anthura polita, s. 

 Paranthura brachiata, N. 

 Ptila-nthura tenuis. 

 Leptochelia algicola, s. • 



The eleven species included in the following list occur also on the 

 coast of Europe. The British species are marked b. 



Astacilla granulata. 

 Limnoria lignorum, B. 

 ^ga i)sora, b. 

 Tanais vittatus, b. 

 Leptochelia algicola, b. 



Gyge Hippolytes, B. 

 Phryxus abdominalis, b. 

 Jsera albifrons, b. 

 Munna Fabricii. 

 Munnopsis typica. 

 Idotea irrorata, b. 



The number of Isopoda included in the present paper is considerably 

 less than are known to inhabit Great Britain, being only about two- 

 thirds as many as are included in Bate and Westwood's work, together 

 with such additions to that fauna as have come to my knowledge since. 

 As has been seen, eight, or nearly one-fifth of our marine species, are 

 identical with those of Great Britain. The number of genera is much 

 more nearly equal. Thirty-one marine genera are enumerated in the 

 present paper, and of these sixteen are also British. The remaining 

 fifteen do not appear to be represented on the British coast, but their 

 place is filled by perhaps a rather greater number of genera. Of the 

 families, neglecting the Oniscidce as not properly included in the present 

 paper, we come to the Bopyridce, which have as yet been but little studied 



* The only specimen yet known is from twenty-one miles east of Cape Cod. 



