65 



clothed with pectinate setae, last joint large, conically produced at the end. 

 Posterior antennae with the outer ramus distinctly biarticulate. Mandibular 

 palp likewise biarticulate, with the outer ramus small or wanting. Maxillae 

 with the exopodal lobe well defined, bisetose. 1st pair of legs with both rami 

 3-articulate, the inner one imperfectly prehensile, being far less produced than 

 in Mesochra, and scarcely bent at the end; middle joint of outer ramus without 

 any seta inside. The succeeding pairs of legs comparatively slender, with the 

 outer ramus much longer than the inner, which is only composed of 2 joints. 

 Last pair of legs with the distal joint more or less produced; inner expansion 

 well developed. 



Remarks. This new genus is established to include the form described 

 in Vol. V, p. 395, as Mesochra exigua. The rather aberrant characters of this 

 small species were noted in that plase, and it was therefore only with some 

 doubt referred to the genus Mesochra of Boeck. Having now had an oppor- 

 tunity of examining some other forms agreeing pretty well in the more general 

 characters with the above-mentioned species, I think that the establishment of 

 the present genus may be fully justified. The most conspicuous differences 

 from Mesochra are found in the structure of the anterior antennae and in that 

 of the 1st pair of legs. The generic name here proposed alludes to the 

 agreement in structure of the anterior antennae to those in some of the Cleto- 

 didce. 3 new species referable to the present genus will be descrited below. 



53. Cletomesochra major, G. O. Sars, n. sp. 



(PI. XLII). 



Specific Characters. Female. Body comparatively more slender than 

 in the type species, with the anterior division only slightly broader than the 

 posterior. Cephalic segment about the length of the 3 succeeding segments 

 combined; rostral plate rather prominent and narrowly truncated at the tip. 

 Urosome shorter than the anterior division and only very slightly tapered 

 behind, its segments minutely denticulate at the hind edge; genital segment 

 not fully attaining the length of the 2 succeding segments combined; last 

 segment nearly as large as the preceding one, with the anal opercle broadly 

 rounded and perfectly smooth. Caudal rami very small, quadrangular in form, 

 with the apical setae comparatively short. Anterior antennae scarcely exceeding 

 half the length of the cephalic segment; the first 3 joints rather thick and 

 gradually somewhat diminishing in size, the other 2, representing the terminal 

 part of the antenna, very unequal in size, the proximal one being quite short, 



