69 



56. Hemimesochra clavularis, G. O. Sars, n. sp. 



(PI. XLV). 



Specific Characters. Female. Body moderately slender, with the 

 anterior division conspicuously inflated in front, almost clavate in form. Cepha- 

 lic segment large and tumid, evenly rounded in front, with the rostral plate 

 abruptly deflexed, so as not being visible in the dorsal view of the animal. 

 Urosome comparatively narrow and somewhat shorter than the anterior division, 

 with the segments sharply marked off from each other and distinctly spinulose 

 at the hind edge, the spinules being arranged in small groups; last segment 

 nearly as large as the preceding one, and having the anal opercle small and 

 perfectly smooth. Caudal rami about the length of the anal segment and 

 somewhat divergent, edges partly spinulose; apical setae of moderate length. 

 Anterior antennas scarcely half as long as the cephalic segment, with the first 

 2 joints comparatively short and combined scarcely longer than the 3rd; last 

 joint rather large and clothed with long and slender setae. Posterior antennae 

 with the basal part distinctly subdivided, outer ramus carrying 3 setae, 2 apical 

 and one lateral. Mandibular palp with the basal joint rather large, though 

 not much expanded, and provided in the middle of the outer edge with a 

 strong ciliated seta replacing the outer ramus. 1st pair of legs much smaller 

 than the succeeding pairs, with the inner ramus scarcely extending beyond the 

 middle of the terminal joint of the outer, its proximal joint somewhat expanded 

 and carrying inside the usual ciliated seta, distal joint of about same length, 

 but much narrower, and armed at the tip with a strong spine accompanied 

 inside by 2 unequal setae; outer ramus without any setae inside, terminal 

 joint with only 2 outer-edge spines. The 3 succeeding pairs of legs well 

 developed, with the inner ramus somewhat exceeding half the length of the 

 outer and resembling in shape that in Mesochra. Last pair of legs with 

 the distal joint very small, sub-quadrangular in form, and only provided 

 vvith 4 setae, the innermost of which is much elongated, the other 3 com- 

 paratively short; inner expansion of proximal joint extending far beyond 

 the distal joint and obtusely truncated at the end; marginal setae 4 in number 

 and of very unequal length, the outermost but one much the largest. 



Colour not yet ascertained. 



Length of adult female 0.53 mm. 



Remarks.- The present form may be easily recognised from any of the 

 other known Canthocamptidce by the peculiar clavate shape of the body, a 

 character which has given rise to the specific name here proposed. 



10 Crustacea. 



