42 MR. E, J. MIEES ON THE IDOTEIDiE. 



The Idotea media, Dana (Pr. Acad. Nat. Sci. Philad. vii. p. 175, 

 1857 ; StimpsoB, Boston Journ. Nat. Hist. vi. p. 504, 1857), from 

 California, is briefly characterized by Dana as allied to I. Oregon- 

 ensis (=1. Wosnesenshii), but is a little narrower. Body smooth, 

 with the sides slightly arcuated; postabdomen li times longer 

 than broad, with the sides nearly parallel, distal end arcuate- 

 truncate and apiculate in the middle. Antennae not longer than 

 one third the body ; flagellum 10-12-jointed, scarcely shorter than 

 the peduncle, nearly naked. Legs nearly naked. Length 10 lines. 



The postabdomeu is 3-jointed, with an additional suture on each 

 side of the last segment, as in I. oregonensis. 



The description does not suffice to distinguish this species from 

 I. Wosnesenshii ; Stimpson merely adds that it is distinguished 

 by its longer postabdomeu. As nothing is said respecting the 

 epimera, it may prove to be allied to or identical with the 

 following. 



Idotea Whitei. (Plate II. figs. 1-3.) 



Idotea Whitei, Stimpson, Proc. Ac. Nat. Sci. Phil. p. 155 (1864). 



Is, according to Stimpson, allied to I. Wosnesenshii , but 

 is very much more elongated, and only differs from I. media, 

 Dana, in its longer antennge. It is described as slender, with 

 the sides slightly convex ; head large ; antenna? nearly two 

 thirds as long as the body, the flagellum equalling the peduncle 

 in length and 16-18-jointed ; first thoracic segment short, less 

 than two thirds as long as the second; postabdomeu segmented, 

 as in I. Wosnesenshii and other members of the group, half 

 longer than broad, slightly narrowing posteriorly, with the 

 extremity rounded, truncate, and bluntly acuminated at the 

 middle ; legs moderately stout. Colour yellowish, minutely 

 punctate with dark grey. Length of body 0"81, length of post- 

 abdomen 0'27 inch. The species inhabits Puget Sound. 



I refer here, with some hesitation, two males in the collection 

 of the Paris Museum, received from California together with 

 three specimens of 1. Wosnesenshii. They agree with Stimpson's 

 description in their more elongated body and the 16-18-jointed 

 flagellum of the antennge, and are further distinguished from 

 1. Wosnesenshii by the form of the epimera of the second to 

 fourth thoracic segments, which reach quite to the postero-latera 

 angles of these segments : the epimera of the second segment are 

 broader anteriorly, and the terminal segment more resembles that 



