6 Messrs. T. and A. Scott on some 



know of any described species similar to this Shetland form 

 we have named it in honour of Mr. Duthie, Fishery Officer, 

 Shetland ; it is because of his interest and zeal for natural 

 history work that we have been able to add considerably to 

 the knowledge of the freshwater Crustacea of the Shetland 

 Islands. 



(?) Canthocamptus parvus^ sp. n. 

 (PL II. figs. 14-22.) 



Description of the Species. — Female. Length '37 millim. 

 (ttj of an inch) . Body moderately stout ; antennules short, 

 six-jointed ; the first tliree joints subequal and robust, the 

 last three also subequal, but considerably smaller than the 

 first three (fig. 15). Secondary branch of the antennae uni- 

 articulate, very small, and bearing a short plumose terminal 

 seta (fig. 16). Mandible-palp small; basal joint moderately 

 stout, bearing at the obliquely truncate end a very small one- 

 jointed branch, which is furnished with three short plumose 

 set£e (fig. 17). Other mouth-organs similar to those in typical 

 Canthocamptus. The first pair of swimming-feet somewhat 

 resemble those of Canthocamptus trispinosus ; the first joint of 

 the inner branches is rather longer than the entire length of 

 the outer branches ; the second and third joints are together 

 equal to about half the length of the first joint, but the second 

 is rather shorter than the third ; the third joint bears two 

 terminal setag, one short and spiniform, the other about twice 

 the length and more slender ; a short seta springs from near 

 the middle of the inner margin of the first joint; there are 

 also a few minute set^ on the outer margins of all the joints 

 (fig. 18). The inner branches of the next three pairs are 

 short and composed of two nearly equal joints ; outer branches 

 elongate, three-jointed, the end-joint rather longer than either 

 of the other two (fig, 19). Fifth pair small, inner portion of 

 the basal joint broadly foliaceous, apex obliquely truncate and 

 bearing five setae of unequal length ; four of them are mode- 

 rately short, and one (the second from the outside) more 

 elongate ; secondary joint subquadrangular, rather longer 

 than broad, and furnished with five small apical sette, the 

 two innermost of which are longer than the others (fig. 21). 

 Caudal stylets very short. 



Male. The male differs little from the female except that 

 the antennules are apparently eight-jointed and of a compli- 

 cated hinged structure adapted for grasping. The inner 

 branches of the third pair of swimming- feet in the male are 

 three-jointed and rather longer than the inner branches of the 



