lO SMITHSONIAN MISCELLANEOUS COLLECTIONS 



greatest postorbital breadth, 1.75; breadth a)t constriction, 1.59 

 inches. 



This species was found by us in great numbers in all parts of the 

 North Pacific Ocean north of the parallel of 50°. The following 

 localities may be mentioned : Sea of Okhotsk ; Awatska Bay and off 

 Chepoonski Noss, coast of Kamchatka; off Matwi Island; in Ber- 

 ing Strait, and in the Arctic Ocean. It occurred on all kinds of 

 bottom, from low-water mark to a depth of 50 fathoms or more. 

 Among several hundred specimens of this species not one of H. 

 aranea was found, although this latter species is said by Brandt to 

 occur in the Sea of Okhotsk. 



The specimens from the waters of Awatska Bay, which are some- 

 what brackish, do not differ from those taken in the open sea. 



Brandt, in the Zoology of Middendorff's "Reise in den Sibiriens," 

 part I, page 79, describes a Hyas from the Sea of Okhotsk, which he 

 considers a variety (alutaceus) of H. coarctatus. He states, how- 

 ever, that it differs from the Atlantic form in the somewhat more 

 strongly granulated (starker chagrinirte) upper surface of the cara- 

 pax, in the broader posterior side of the body, and in the broader 

 hands. These characters are certainly not those of our species, 

 and for this reason we have not applied to the Pacific form the name 

 alutaceus. In some of the larger specimens the surface is indeed 

 granulated to some extent, particularly at the summits of the swell- 

 ings ; but specimens of ordinary size are always much smoother than 

 any from the Atlantic. It is not impossible, therefore, that there is 

 still another species in the North Pacific. 



Genus AIICROPISA Stimpson 



Micropisa Stimpson, Proc. Acad. Nat. Sci. Phila., ix, p. 217 [24], 1857. 



It has been found necessary to institute a genus for the reception 

 of a small Pisa-Wke. crustacean which was taken in considerable 

 numbers at the Cape de Verde Islands. It has a short and broad, 

 ovate carapax and flattened rostrum. The orbits are much less 

 complete than in Pisa, and have a single fissure above. It resembles 

 Scyra in many respects, but the external antennae are not concealed 

 beneath the rostrum. The outer maxillipeds resemble somewhat 

 those of Pisa; but the outer angle of the almost heart-shaped third 

 joint is strongly projecting; and there is no notch for the reception 

 of the fourth joint; the palpus is broad. 



