1G2 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Livoneca ovalis White, List Crust. Brit. Mns., p. 1C9, 1R47. — Cymothoa oralis Say, 

 Jour, Acud. Nat. Sci. Pliil., vol. i, p. 394, 1818. 



White and several other British carcinologists use the orthography 

 Lironeca; but iu the Dictionuaire des Sciences natiirelles, tome xii, 

 where the genus is established by Dr, Leach, the name occurs, in French 

 and Latin, nine times on pages 352 and 353, spelled always with v as the 

 third letter. I have, therefore, adhered to that orthography, although 

 there is reason for supposing that Dr. Leach intended to use the form 

 Lironeca. 



Parasitic on Bluefish, etc. ; not yet found north of Cape Cod. 



Anthura polita Stimpson, Proc. Acad. Nat. Sci. Pbil., vol. vii, p. 393, 1855. — Anthura 

 hrunnea Harger, Eep. U. S. Fish Com., part i, p. 572 (278), 1874. 



A southern species, not found north of Cape Cod until the summer of 

 1878, when it was taken at Gloucester, Mass. Usually found among 

 Eel-grass or mud in shallow water. 



Paranthura hxachia.ta^A)ithHra h'acMata Stimpson, Mar. Invert. Grand Manan, p. 

 43, 1853. 



A northern species, but found as far south as Vineyard Sound, from 

 27 to 115 fathoms. 



Ptilanthura tenuis Harger, Am. Jour. Sci., Ill, vol. xv, p. 377, 1878. 



Rare, but found throughout the New England coast. The remarkably 

 ■elongate flagellum of the antennulce belongs to the males only. 



'Gnathia ceiina. = Prauiza cerina Stimpson, Mar. Invert. Grand Manan, p. 42, pi. iii, 

 lig. 31, 1853; and, also, Anceiis American ns Stimj)son, op. cit., p. 42, 1853; the 

 former being the female form and the latter that of the adult male. 



A northern species, not yet found south of Cape Cod, occurring in 

 from 10 to 220 fathoms, and, in the young stages, parasitic on fish. 



Tanais vittatus Lilljeborg, Bidrag til Kiinn. Crust. Tanaid., p. 29, 1865. — Crossnriis 

 riftattis Rathke, Fauna Norwegens, (Nova Acta Acad., vol. xx,)ii. 39, pi. i, figs. 

 1-7, 1843. 



This species has been found at Koank Harbor, Conn., and will proba- 

 l)ly be found at other localities on our coast. I have had no European 

 specimens for comparison, and, unfortunately, have not had access to 

 some important European literature on the subject, but do not know of 

 any character by which to distinguish it from Eathke's species, and have 

 therefore regarded it as identical. 



This genus is well separated from the next by the pleon, which bears 

 onlj' three pairs of pleopods and uniramous uropods, and by the remark- 

 able incubatory sacs attached to the fifth thoracic segment of the 

 females, and unlike anything else found among the Isopoda. They have 

 been described by Rathke, Willemoes-Suhm, and others. 



Leptochelia algicola= P«)-«f« (mis rt/r/jco/a Harger, Am. Jour. Sci., Ill, vol. xv, p. 377, 

 1878. — Leptochelia Echcardsii Bate and Wcstwood, Brit. Sess. Crust., vol. ii, p. 

 134, 1868, (males). — Tauais /?»m Harger, Rep. U. S. Fish Com., part i, p. 573 

 (279), 1874, not of Stimpson. 



A male specimen, received from Guernsey, through the kindness of 



