175 



female scarcely subdivided. Anterior antennae of the usual structure, 7-arti- 

 culate. Posterior antennae more or less strongly developed, in some cases 

 pronouncedly prehensile, in other cases imperfectly prehensile. Oral parts on 

 the whole of normal structure, the posterior maxillipeds in female having the 

 dagtylar joint well developed, spiniform. Natatory legs with both rami distinctly 

 3-articulate; inner ramus of 4th pair however in most cases somewhat smaller 

 than in the other pairs. Last pair of legs comparatively small, bisetose. 



Remarks. This genus, established by Canu, is nearly allied to Modioli- 

 cola; but differs in the more strongly chitinised integuments, the well defined 

 rostrum, and the somewhat unlike structure of the posterior antennae and the 

 posterior maxillipeds. 5 species referable to this genus will be described in 

 the sequel. All these have been found occasionally among dredged material; 

 but is is very likely to believe, that they in reality, like the species of the 

 preceding genus, lead a semiparasitic existence, probably within different 

 bivalve Molluscs. This has indeed been stated to be the case with the type 

 of this genus, Hermannella rostrata Canu, as also with H. maxima (Thomps.). 



94. Hermannella valida, G. O. Sars, n. sp. 



(PI. XCVI1I). 



Specific Characters. Female. Body rather stout and robust, with the 

 anterior division considerably dilated in front, its greatest width equalling about 

 half the length of the body. Cephalic segment very large and expanded, 

 exhibiting behind a rather slight transverse suture defining the cephalon from 

 the 1st pedigerous segment, lateral edges evenly curved throughout. Epimeral 

 plates of the 2 succeeding segments obtusely rounded, those of penultimate 

 segment acutely produced. Last segment of trunk very small. Tail compara- 

 tively short, scarcely longer than the 4 free trunkal segments combined; genital 

 segment occupying about half the length of the tail, and somewhat dilated in 

 the middle; anal segment considerably longer than the preceding one. Caudal 

 rami much shorter than that segment, and only slightly longer than they are 

 broad, each having close to the base outside a small bristle; caudal setae not 

 much different in length, that of the outer edge attached near the end. Anterior 

 antennae rather slender and of quite normal structure. Posterior antennae very 

 powerfully developed and pronouncedly prehensile, 1st joint much the largest 

 and obliquely produced at the end; the 3 succeeding joints successively 

 diminishing in size, the last one armed at the end with a single very strong 

 claw accompanied by a number of unequal setae. Maxillae with the masticatory 



