CRUSTACEA NORTH PACIFIC EXPLORING EXPEDITION 21 



article subcylindrical and slender. Abdomen consisting of six seg- 

 ments, all of which are exposed by the shortness of the carapax pos- 

 teriorly ; extremity broad. Dimensions of carapax : Length, 0.385 ; 

 breadth, 0.325 inch. 



This species was dredged on a muddy bottom in 6 fathoms, in the 

 harbor of Port Jackson, Australia. 



Genus ACHx^OPSIS Stimpson 

 Achccopsis Stimpson, Proc. Acad. Nat. Sci. Phila., ix, p. 219 [25], 1857. 



In this genus the general appearance resembles that of AcJkhus, 

 and the terminal joints of the feet of the posterior three pairs are 

 falciform. As in Btirypodius, the eyes are retractile, but without 

 orbits, and the external antennae are not concealed beneath the ros- 

 trum. The antennulary fossse are very large, and excavated in the 

 under side of the horns of the small bifid rostrum. The basal joint 

 of the external antennae is narrow and placed almost in a vertical 

 plane, as in Leptopodia. 



20. ACH^OPSIS SPINULOSUS Stimpson 



Plate III, Fig. s, 50 



AchcEopsis spinulosus Stimpson, Proc. Acad. Nat. Sci. Phila., ix, p. 219 

 [25], 1857. 



Description of a developed female. The carapax is rather thick 

 and convex above, the sides rounded ; the regions not strongly de- 

 fined, and rising but little beyond the general surface. The surface 

 is minutely and inconspicuously pubescent. The spines on the upper 

 surface' of the carapax are all small, about equal in size, and very 

 sharp and slender; there are three on the gastric region, one placed 

 posteriorly in the median line, the other two on the sides between the 

 median and the postocular spines. The somewhat protuberant 

 summit of the cardiac region is unprovided with a spine, but there 

 are two on each branchial region. Four minute spines on the hepatic 

 region and a few placed along the inferior lateral margin of the 

 carapax. The rostrum is rather longer than it is broad at its base, 

 and divided for more than half its length, with tlie iiorns acute. 

 The small, sharp praeocular spine points obli(|ucly upward and for- 

 ward. The ocular peduncles in length equal about half the inter- 

 orbital space; they bear a slight tooth inferiorly in front and a minute 

 spine at the summit of the eye. The narrow basal joint of the ex- 

 ternal antennae curves upward and slightly outward at the base of 



