]60 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Idotea irrorata P^lwards, Hist. nat. des Crust., tome iii, p. 132, lb40. — Sfenosoma irro- 

 raia Say, Jour. Acad. Nat. Sci. Phil., vol. i, p. 42o, 1818. — Idotea tricuspidata 

 Desmarest, Diet, des Sci. nat., tomexxviii, p. 373, 1823; Consid. Crust., p. 289, 

 1825. 



This species is commoD tbroiigliout the coast of New England, but is 

 more abundant southward, being to a great extent replaced toward the 

 north by the next species. 



A comparison of English and European specimens with our own 

 leaves no doubt of the identity of the species on the opposite coasts of 

 the Atlantic. Being a common European species, it has been mentioned 

 by many authors under a variety of names, which are more fully quoted 

 and discussed in the report. Say's name appears to be the earliest that 

 can be certainly connected with the species. 



Idotea phosphorea Harger, Rep. U. S. Fish Com., part i, p. 569 (275), 1874. 

 Found throughout the coast, but more abundant northward. 



Idotea robusta Kroyer, Naturhist. Tidssk., II, Bind ii, p. 108, 1846; Gaimard's Voyage 

 en Scaudinavie, etc., Atlas, pi. sxvi, fig. 3 «-»•, 1849. 



A pelagic species. 



Synidotea nodulosa Harger, Am. Jour. Sci., Ill, vol. xv, p. 374, 1878. — Idofheanodulosa 

 Kroyer, Naturhist. Tidssk., II, Bind ii, p. 100, 1846; Gaimard's Voyage en 

 Scandinavie, etc.. Atlas, pi. xxvi, fig. 2, 1849. 



A northern species, found at Halifax, N. S., and 125 miles southward, 

 in from 16 to 190 fathoms. Also from George's Bank. 



Synidotea hicuspida^ Idotea hicuspida Owen, Voyage of the Blossom, Crustacea, p. 

 92, pi. xxvii, fig. 6, 1839. — Idotcea marmorata Packard, Mem. Soc. Nat. Hist. 

 Boston, vol. i, -p. 296, pi. viii, fig. 6, 1867. — Idotea pulchra Lockington, Proc. 

 Cal. Acad. Sci., vol. vii, p. 45, 1877. 



The determination of the synonymy of this species rests i)rincipally 

 upon the work of Messrs. Streets and Kingsley in the Bulletin of the 

 Essex Institute, vol. ix, p. 108, 1877. It has not yet been found south 

 of the Grand Bank. 



Erichsonia filiformis Harger, Rep. U. S. Fish Com., part i, p. 570 (276), pi. vi, fig. 26, 

 1874. — Stenosoma filiformis Say, Jonr. Acad. Nat. Sci. Phil., vol. i, p. 424, 1818. 



A southern sijecies, not yet found nortli of Cape Cod. 



Erichsonia attenuata Harger, Rep. U. S. Fish Com., part i, p. 570 (276),i>l. vi, fig. 27, 

 1874. 



Great Egg Harbor, New Jersey, and Noank, Conn. The species will 

 probably be found at other localities, among eel -grass, on the southern 

 shore of New England. 



Epelys trllobus Smith, Rep. U. S. Fish Com., parti, p. 571 (277), pi. vi, fig. 28, 1874.— 

 Idotea triloha Say, Joui-. Acad. Nat. Sci. Phil., vol. i, p. 425, 1818. 



A southern species, rare north of Cape Cod, but extending, with some 

 other southern species, to Quahog Bay, on the coast of Maine. 



