ON CRUSTACEA BROUGHT BY DR WILLEY FROM THE SOUTH SEAS. 635 



The name of the genus is framed in compliment to H. J. Hansen, whose work 

 has shed so much light on the structure of the Cirolanidae and the nearly related 

 families. 



HaNSENOLANA AXISOPOUS, n. sp. 

 Plate LXVIII a. 



Head twice as broad as long, more than half as broad as the peraeoii, deeply 

 immersed, front broader than the straight hind margin, truncate, but with small rostral 

 point and the lateral angles rounded, surface wrinkled. Peraeon only slightly convex, 

 first segment the largest, wrinkled, its front angles much produced, rounded, second 

 segment the shortest, the rest subequal, with hind margins faintly nodulose, the side- 

 plates successively more acute and reaching further beyond their respective segments, 

 those of the seventh .segment overlapping the fourth pleon segment completely. Pleon 

 broad, widening to the fourth segment, first segment and angles of second and fifth 

 concealed, angles of the fourth reaching the apices of the side-plates of the seventh 

 peraeon segment, fifth segment at the middle rather longer than the fourth. Terminal 

 segment with a breadth at its base more than twice its length, which exceeds that 

 of the four preceding segments combined, sides curved, apex slightly curved, less than 

 half the basal breadth. Earlier segments of ploon have a median lobe which narrows 

 to the base of the terminal segment, thence to the apex forming a low carina. By 

 help of the second antennae above and the uropods below the whole body is strikingly 

 parallel-sided ; many parts of it carrying small hairs. 



E\'es placed at the antero-lateral corners of the head, small, but with several 

 (about eighteen) ocelli. 



First antennae shorter than the peduncle of the second, very slender, first joint 

 the longest, width not uniform, second shorter and much narrower, followed by what 

 appears to be an extremely short third peduncular joint, flagellum seven-jointed, a 

 little shorter than the first, a little longer than the second, joint of the peduncle. But 

 this account must be modified if, as is quite probable, the first joint of the peduncle 

 is composite, representing the first and second joints in coalescence. 



Second antennae. Peduncle much stouter than in first pair, third and fourth joints 

 equal, fifth a little longer than either, flagellum slender, as long as the jjeduncle, 

 twenty-one-jointed. 



Frontal lamina widening to the rounded apex, its base perhaps concealed by a 

 rounded median projection of the wide, very short epistome. Upper lip broad and short. 



Mandibles. The trunk from a broad base narrows to the cutting edge, which on 

 the right mandible is divided into three strong tinequal teeth, on the left has a 

 couple of denticles at the top and a tooth below. //; situ, as described by Hansen 

 for the Cirolanidae in general, the cutting edge of the right mandible is covered by 

 that of the left. The blade-like molar has the usual row of teeth within the thin 

 convex front edge ; between this and the cutting edge is the part called ' lacinia 

 mobilis' by Hansen, here sun'ounded by eighteen spines and preceded by a thin, slightly 

 spinulose lobe, apparently attached to the cutting edge. Second joint of palp longer 



w. V. 84 



