KONGL. SV. VET. AKADEMIENS HANDL1NGAR. BAND. 22. N:0 7. 383 



Syn. 1877. Phronima pacifica, TH. STREETS. "Contributions to the Natural 



History ofthe Hawaiian and Fanning 

 Islands and Lower California". 

 Bulletin of the United States Na- 

 tional Museum. N:o 7. 1877, 

 p. 128. 



» » » 1883. »A Study of the Phronimidre of the 



Northern Pacific Surveying Expe- 

 dition". Proc. of the United States 

 National Museum. Vol. 5, p. 6, 

 pi. 1, fig. 3 and 3 a. 



» » » Th. Stebbing. 1888. "Report on the Amphipoda». Voy. 



of H. M. S. Challenger. Zoology. 

 Vol. 29, p. 1348, pi. 159. 



From the original description given in 1877 by Streets I reproduce the following 

 passage : 



» — — — First pair of gnathopoda having the meros produced, and with the inferior 

 margin furnished with minute spinules, one of which, larger and longer than the rest, at the apex; 

 the superior border of the carpus arched, produced antero-inferiorly, and very slightly anteriorly; 

 produced part not reaching half the length of the propodos; the anterior margin closely set with 

 acute, triangular teeth; one at the inferior apex, long and slender; the inferior margin finely 

 serrated; propodos about the same length as the superior border of the carpus, cylindrical, ar- 

 cuate, slightly tapering toward the distal extremity, finely serrated on the inferior surface, and 

 three or four longer spines on the superior surface; dactylos short, about one-fourth the length 

 of the propodos, curved, and notched on the under surface, posterior to the apex; on either side 

 of the base is a wing-like plate. The second pair of gnathopoda longer than the first pair, and 

 the anteroinferior angle not produced to the same extent; in other respects they are similar. 

 The first pair of thoracic feet shorter than the second, and much longer than the gnathopoda; 

 the posterior margin of the carpus and propodos of both pairs minutely spinulose; dactylos 

 minute. The third pair chelately developed; carpus large, irregularly quadrilateral, almost as 

 broad as long, the inferior surface rounded, and the antero-inferior angle produced as a long 

 tooth; on the middle of the anterior surface is a large crenulated tubercle, from which rise five 

 or six long, straight hairs. In specimens from the 0,is to the 0,20 of an inch long, there are, 

 in the position of the tubercle, two or three sharp, prominent teeth, springing from a slightly 

 raised base; and the angle of the carpus is less projecting in the same specimens. Propodos 

 bowed; when flexed on the carpus reaching to the apex of the tooth at the inferior angle — in 

 smaller specimens somewhat longer; a low convexity on the inferior surface opposite the crenu- 

 lated tubercle of the carpus; the prominence not crenulated; inferior surface bimarginate. Dac- 

 tylos present, minute. The posterior apex of the coxa of the third pair acute, prominent; the 

 meros projecting posteriorly and rounded. The two posterior pairs of thoracic feet subequal, 

 shorter than any of the preceding pairs. Telson rudimentary.)) 



It is possible that the larger specimens mentioned in the above description do not 

 belong to Phronima pacifica. In 1882 Streets gave the following new details: 



» — — The fifth pair of legs (= the. fifth pair of perceopdda) are relatively shorter, when 

 compared with those of atlantica; a prominent spine on the posterior extremity of the basal joint, 

 in front; the third joint short, broad, and considerably arched above; the fourth joint (palm) 

 broadly quadrate, almost as broad as long, the superior border rounded posteriorly to the arti- 

 culation of the third joint, the lower border slightly curved, the character of the dentition on 

 the anterior border similar to that of atlantica in the general arrangement of the teeth, but the 

 teeth are not nearly so prominent, or pointed, the lower, single tooth but slightly separated from 

 the larger crenulated tubercle; the prolonged inferior angle more curved upward, and shorter 



