CLAVELLA CANTHARI. 225 



sea-bream (GantJiarus lineatux) and the common sea- 

 bream (Pagellus centrodontus). On Cantharus lineatus, 

 captured in the North Sea in November 1910, as well 

 as on a few subsequent occasions, fcroyer obtained 

 what appears to be the same species on Pagellus 

 centrodontus. 



The characters by which this species seems to be dis- 

 tinguished are the proportional length of the cephalothorax, 

 the small lobe on each side of its promixal end, the peculiar 

 appendage by which the species is anchored to the gill 

 filament, and the densely ciliated central lobe of the posterior 

 margin of the genital segment. Some of the specimens 

 examined by us have exhibited slight differences, but they 

 all agree in the more important characters mentioned above. 



11. Clavella alata Brian. 

 (Plate LXIX, figs. 4-6.) 



1906. Clavella alata Brian. (21) p. 114, pi. iii, fig. 5 ; pi. xx, figs. 5 and 6. 



Female. Short and stout. Cephalothorax reaching 

 only to about, or slightly beyond, the end of the genital 

 segment; at the base of the cephalothorax a small 

 horn-like process projecting outwards on each side. 

 The second maxillipeds apparently completely coalesc- 

 ent, very short, tapering slightly towards the tip, 

 which is provided with a rounded cartilaginous knob. 

 Genital segment short and stout, subglobose or pyri- 

 forin, greatest width about equal to the length, pos- 

 terior end subtruncate or broadly rounded ; the middle 

 portion, however, slightly produced, and on each side of 

 this slightly produced part is the attachment of the short 

 and tolerably stout ovisacs. The antennules, antennae, 

 and several mouth-appendages apparently not differing 

 greatly from those of other species of the genus. 

 Antennules short, moderately stout, indistinctly seg- 

 mented, and bearing a few apical setae ; mandibles 

 very slender, but the first maxillipeds tolerabty en- 

 larged and uncinate. The entire length, exclusive of 

 the egg-strings, is about 3 mm., while the egg-strings 

 are about 2 mm. in length. Colour yellowish. 



VOL. I. 15 



