406 BULLETIN OF THE BUREAU OF FISHERIES. 



This little crustacean appears to be one of great rarity in the Beaufort region and for a number of 

 years has not been taken at all. In the collection of the laboratory of the Biu-eau of Fisheries there is 

 a single mutilated specimen without any data. Another was taken, but unfortimately lost, during the 

 summer of 1914 while the Fish Hawk was dredging in Lookout Bight. The species was originally 

 described by Stimpson from a specimen obtained at Beaufort and was later collected by Prof. Webster 

 and recorded by Kingsley. 



Tribe THALASSINIDEA. 



Anomura of a somewhat shrimplike form having the cephalothorax compressed, the 

 abdomen large, symmetrical, extended and sometimes with well-developed pleura, and 

 the appendages of the sixth segment usually adapted for swimming. The carapace and 

 the covering of the abdomen are often more or less membranous and the last articles 

 of the second to fourth pairs of legs are not curved and flattened. 



This tribe comprises 4 families of which i is represented in the Beaufort faima. 



Family CALLIANASSIDAE. 



Thalassinidea having a "linea thalassinica," small abdominal pleura, no sutures on 

 the sixth abdominal appendages, no podobranchs on any of the legs, and broad append- 

 age on the third to sixth abdominal segments. 



Of 13 genera, 3 are represented in the Beaufort region. 



KEY TO THE GENERA OP THE BEAtTPORT REGION. 



a. Rostrum small; first two pairsofpleopods different from the following three pairs; chelipeds dissimilar 

 and unequal. 



b. Inner bladeof lu-opods oval; telson nearly flat above Callianassa. 



bb. Inner blade of uropods narrow, its margins nearly parallel; upper surface of telson with a deep 



median groove Callichirus. 



aa. Rostrum large; second pair of pleopods like the following three pairs; chelipeds alike and sub- 

 equal Upogebia. 



G«nus CALLIANASSA Leach. 



Callianassa Leach, 1814, p. 400. 

 Callianassa stimpsoni Smith. PI. xxrx, fig. 5. 



Callianassa stimpsoni-SoAlih, 1873, p. 549; Kingsley, 1880a* p. 410; Sumner, 1911, p. 666. 



Integument throughout smooth and shining, thin, but more than membranaceous. Cephalothorax 

 about one-third the length of the abdomen, very thin shelled on the sides but with an oval, thickened 

 plate on the dorsal region; rostrum and postorbital spines subequal, small and acute. Abdomen with 

 the third, fourth, and fifth segments of about the same width and each with a small patch of fine hairs 

 on the posterolateral angle; sixth segment narrowing; telson small, flat, rounded. Eyestalks small, 

 flat, pointed, and with the tips curved outward. Antennular peduncle about two-thirds as long as the 

 carapace, densely ciliate beneath, the flagella about as long as the distal article of the peduncle. An- 

 tenna slender, longer than the cephalothorax, its peduncle geniculate between the second and third 

 articles. First pair of legs in the male very dissimilar; the larger one mth a prominent tooth at the 

 proximal end of the meros beneath ; carpus articulating with meros by the extreme upper angle, its width 

 equal to that of hand; fingers of about equal length, hairy and with incurs'ed tips. Uropods with both 

 blades broad. 



Length of a male, 59 mm.; carapace, 14.5 mm. 



Although recorded by Kingsley in 1879, this crustacean was not met with again in the Beaufort 

 region imtil 1914, when a small specimen was brought in from the Blackfish Banks by the steamer Fish 

 Hawk. 



