38 MB. E. J. MTEES OW THE IDOTEIDJE. 



In the large series in the collection of the Paris Museum the 

 following are of interest on account of the locality : — specimens 

 of both sexes from Algiers (M. Lucas), and designated Idotea 

 algirica, Lucas ; the type specimens of I. rug&ta, M.-Edw., from 

 the open sea, Indian Ocean, and other specimens from Sumatra 

 (M. Bourdes), designated I. rugosa ; one of these measures 1^ inch 

 (30 mm.) in length : also examples from St. Helena (Dussumier) ; 

 Teneriffe (Quoy & Gaimard), small and of pale colour ; a fine 

 series from the Cape of Good Hope, and four specimens from 

 Port Jackson (M. Freycinet), &c. 



In the specimens designated I. algirica by Lucas the body is 

 not pubescent, and the lateral serratures caused by the projecting 

 epimera, although strongly marked, are not so prominent as in 

 Lucas's figure. Dr. Heller notes the occurrence of this species, 

 but rarely, at Lesiua. 



Idotea Irevicornis of Eathke, nee Edw., "Beitr. zur Eauna Nor- 

 wegens," in Nova Acta Acad. Cses. Nat. Curiosorum, xx, p. 24 

 (1843), from Christiansund, is described too briefly for me to be 

 certain of its systematic position. The eyes are very large and 

 black; the antennae have a 7-8-jointed fiagellum and are altogether 

 Tery thick, and reach, at farthest, to the second thoracic segment ; 

 the postabdomen is in its posterior portion not so much ridged as 

 very bluntly angulated ; it is rounded at the end, with only very 

 feeble indications of a median apical point ; moreover the post- 

 abdomen is short, compressed, and but little nari'owed towards its 

 apex. The legs are sliort and thick, yet the posterior pair reaches, 

 because of the smallness of the postabdomen, a little beyond it, 

 which is not usual in the genus Idotea. Colour olive-green, in 

 some specimens approaching black, in others yellow ; no mottlings 

 were noticed. Length of a male not exceeding 7^ lines ; female 

 much smaller. 



It is not improbably identical with I metallica. 



Idotea. maegabitacea. 



Idotea margaritacea, Dana, U.S. Explor. Exped. xiv. Crust, p. 700, 

 pi. xlvi. fig. 2 (1853) ; Miers, Cat. Neio-Zeal. Crust, p. 92 (1876). 



Is apparently very closely allied to the preceding species, and 

 should perhaps not be regarded as distinct from it. Dana, how- 

 ever, describes the front as 3 -toothed, the three teeth very low, 

 one occupying either angle, and the third, which is less distinct, 

 the middle of the front ; the outer are subacute, and the spaces 



