32 MK. E. J. MIEUS ON THE IDOTEIDJE. 



As we learn from Mr. Harger's Eeport, it is found associated 

 with the last among rocks and weed along the entire coast of 

 New England, and extends northward to Halifax, Nova Scotia, 

 and the Grulf of ISt. Lawrence. It appears to have a more northern 

 range on that coast than I. marina. The colour is very varied, 

 but never of the striped pattern so common in I. marina. 



To this from belong two out of three specimens from Pictou, 

 Nova Scotia (Lieut. Kedman), in the collection of the British 

 Museum, to which White applied the MS. name of I. oxyii,ra. 

 The third specimen I refer to 1. marina. Nearly allied as the 

 two forms undoubtedly are, the character of the epimera, with 

 the other distinctions mentioned, apparently suffice to distinguish 

 them, at least as varieties. 



There appears to be no sufficient reason to distinguish Idotea 

 qramdosa of Eathke (Beitr. Fauna Norwegens, in Nov. Act. Nat, 

 Curiosorum, XX. p. 23, 1843), from Christiansund and Drontheim, 

 from the American J. ^/iosjj^orea. Eathke's specimens scarcely 

 differ (according to his description), except in their shorter au- 

 tennpe and colour, characters of little value. His specimens were 

 of small size (6 lines), but have a granular carapace, and the form 

 of the terminal postabdominal segment is similar. As, however, 

 the form of the epimera is not mentioned, I retain for the pre- 

 sent Harger's name for the specimen from Nova Scotia in the 

 Museum collection. 



Idotea ochotensis. (Plate I. figs. 8-10.) 



Idotea ochotensis, Brandt, in Middendorff's Sibirische Reise, ii. Cr. 

 p. 145, pi. vi. fig. 33 (1851). 



In this species the body is elongated, raised like a keel in the 

 middle of the line, sloping, smooth, and naked on the sides. The 

 anterior frontal margin is deeply emarginate and compressed 

 posteriorly ; antero-lateral lobes very conspicuous, arcuated, bent 

 downward and forward, so as wholly to cover the basal antennal 

 joint. All the thoracic segments broad on the sides, very straight- 

 edged, with their posterior and inferior angles more or less right 

 angles. Postabdomen composed of three distinct segments, the 

 terminal segment much elongated, quadrangulate, with straight 

 lateral margins ; posterior margin with a triangulate tooth-like 

 process, which gives out a keel that extends along the whole 

 length of the dorsal surface of the segment in the median line. 

 Eyes small. Anteunules short, not reaching to the end of the 



