ME. E. J. MIEES ON THE IDOTEIDJi:. 65 



characters approaches Edotia, from which it is distinguished by 

 the distinct epimera. 



Edotia. 



Edotia, Guerin-Meneville, Icon. Regne Animal, Cr. p. 34(1829-44); 



Dana, Amer. Journ. of Sci. ^- Arts, (ser. 2) xiv. p. 300 (1852); id. 



U.S. Expl. Exp. xiv. [Cr. 2), p. 697 (1853). 

 Anisonotus, White, List Crust. Brit. Mus. p. 9/ (1847), descript. 



nulla. 

 Desmarestia, Gay, Hist, de Chile, Zool. iii. Cr. p. 284 (1849); Dana, 



t. c. p. 1595 (1853). 

 ? Epelys, Dawa, Amer. Journ. of Sci. ^ Arts, (ser. 2)viii. p. 426 (1849), 



xiv. p. 300 (1849); id ? U.S. Expl. Exp. xiv. [Cr. 2) pp. 697, 705 



(1853); 1 Harger, Isopoda in Rep. U.S. Fish Comm. pt. vi. p. 357 



(1880). 

 Synidotea, Harger, Amer. Journ. of Sci. Sf Arts, (ser. 3) xv. p. 374 



(1878) ; id. Isopoda in Rep. U.S. Fish Comm. pt. v. p. 350 (1880). 



Body rather convex, usually of a firmer and more solid struc- 

 ture than in Idotea, more or less ovate, with the sides narrowing 

 rapidly from the third or fourth thoracic segment to the distal 

 end of the postabdomen. Postabdomen uniarticulate or biarticu- 

 late. Antennules slender, longer or shorter than the head. 

 Antennae either short, with an obsolete or with a minute rudi- 

 mentary flagellura, or well developed, with the flagellum multi- 

 articulate. Epimera not distinct, and not evident in a dorsal 

 view, i. e. not distinctly articulated with the thorax. Legs mode- 

 rately robust ; the three anterior pairs with the penultimate 

 joints or palms not greatly dilated ; dactyli strong. Operculum 

 with the basal or proximal plates having their outer surface 

 crossed by an oblique raised line (in the species I have exa- 

 mined). 



§ Antennas loell developed, with the flagellum composed of several 

 joints. Postabdomen uniarticulate, (Synidotea.) 



The only distinction that can be cited to separate the species 

 of Synidotea from Edotia, viz. the long antennae with more nume- 

 rously articulated flagellum, is, I think, scarcely of generic im- 

 portance, since the length of the flagellum is subject to consider- 

 able variation, even in difi"erent individuals of a single species. 

 In JEdotia {Synidotea) nodulosa the flagellum is only about 9- 

 jointed, the last tAVO joints being very minute. 



LINN. JOUEN. — ZOOLOGY, VOL. XVI. 5 



