BY GEO. M. THOMSON, F.L.S. 57 



the shortest of all ; the lateral portions of the third, fourth, 

 and fifth are greatly produced backwards, and have their 

 margins rounded and edged with short acute spines. The 

 uropods have a very large basal joint, its outer portion re- 

 semblingthe lateral portion of the preceding segment, but 

 with the inner margin only about half as long as the outer 

 and transversely truncate ; the outer rami are stout, blunt, and 

 spinose ; the inner are long and very slender, are tipped by a 

 long bristle and have their margins finely scabrous ; they 

 appear to spring from the very base of the uropods and lie 

 together in the median line. 



The whole appearance of these animals suggests that they 

 may be in reality, as Dana suggested, only young forms, but 

 though I have collectea them in abundance on the New Zea- 

 land coasts during several years past, I have never met with 

 any other species resembling them. 



Harger's genus Adoniscus (Amer. Journ. Sci. iii., Vol. 

 XV. p. 373, 1878), must evidently be relegated to Actoeia, 

 the characters of which were so imperfectly defined by Dana. 



Family jEgidce. . 

 11. Bocinela sjjongicola, u. sp. (PI. iii., figs. 3-8.) 



Two specimens belonging to this genus were sent me by 

 Mr. A, Morton, with the remark that they were found in 

 some sponge which had been dredged ; the exact locality, 

 however, was not stated. The following is a description : — 



Body (fig. 3) scarcely convex, smooth, narrow, oval in form, 

 the length being three times as great as the breadth. Head 

 short, rounded in front ; eyes occupying nearly the whole of 

 the segment, crescent shaped. The thoracic segments in- 

 crease slightly in length to the sixth, which- is the longest. 

 Epimeras small, those of the last three pairs produced back- 

 wards (especially the last) into acute angles. Last abdominal 

 segment triangular, pointed, longer than the anterior portion 

 of the abdomen, setose on the posterior half of the margin. 



First antennae reaching nearly to the end of the thoracic 

 segment, hardly separated at the base by a minute acute pro- 

 cess of the cephalon; peduncle and flagellum sub-equal in 

 length, the latter about fourteen-jointed setose, the second 

 joint as long as the three succeeding. Second atennae half as 

 long again as the superior; joints of the peduncle slightly 

 increasing in length to the fifth, which is the longest ; flagel- 

 lum as long as the peduncle, about fourteen-jointed. 



Mandibles (figs. 4 and 5) with the strong basal portion 

 ending in a minutely two-lobed extremity, viz., a sub-acute 

 tooth and a shorter rounded lobe; palp with the joints sub- 

 equal in length, the last curved setose on its inner margin 



