new and rare British Crustacea. 3 



maxillas, combined with the remarkably powerful posterior 

 foot-jaws and fifth pair of feet, are fairly satisfactory evidence 

 of its parasitic habits. This species, if not congeneric with 

 Clapar^de's genus Chiusia, is at least very closely allied to 

 it, and therefore till further specimens, especially male, be 

 obtained, to permit of a more thorough examination being 

 made, we prefer meanwhile to place it in that genus. 



(?) Clausia C^uthce somewhat resembles Glausia Luhbockiij 

 Claus, in general appearance; but the difference in the 

 structure of the antennules and fifth pair of feet distinguishes 

 it at once from that species. 



Maraenobiotus Vejdovshyi, Mrazek. 

 (PI. I. figs. 13-21; PL ir. fig. 23.) 



This cm-ious freshwater Copepod was described for the first 

 time by Herr Al. Mrazek in the seventh volume of the 

 'Zoologische Jahrbiicher' (1893), p. 103, Taf. iv. figs. 17- 

 32, and Taf. v. figs. 33-37. The following brief description 

 (with drawings) is prepared from Scotch specimens : — 



Female. Length "67 millim. (y^^y of an inch). Body slender 

 and elongate (fig. 13), and in this respect somewhat similar 

 to Ophiocamptus. Antennules short, eight-jointed (PL II. 

 fig. 23). Secondary branches of antennge two-jointed, the 

 end-joint shorter than the other (PL I. fig. 14) . Both branches 

 of the first pair of swimming-feet two-jointed and nearly of 

 equal length (fig. IS). Inner branches of the next three 

 pairs two-jointed and considerably shorter than the three- 

 jointed outer branches (fig. 19). Fifth pair small ; inner 

 portion of the basal joint not much produced, broadly truncate 

 and furnished with four moderately short and subequal 

 plumose seta3 on the margin of the truncate apex; secondary 

 joint very small, ovate, and provided with three terminal 

 setEe, the inner one somewhat like those on the basal joint, 

 the other two subequal and fully twice as long (fig. 20). 

 Caudal stylets short and stout; the principal seta of each 

 stylet is articulated at the base and dilated, as shown in the 

 drawing (fig. 21). 



Habitat. Loch Vennachar, Perthshire ; not very common. 



Bemarks. This species, which is an addition to the British 

 fauna, is readily distinguished from other British Harpactids 

 by the structure of the first pair of swimmmg-feet, both 

 branches of this pair being two-jointed ; the mandibles, 

 maxillee, and foot-jaws resemble those of Canthocamptusy 

 except that the mandible-palp is rudimentary and represented 

 by a few sctaj that spring from a papilliform lateral process. 



