

197 



propriate for the present form, which in reality is much the largest of all the 

 known species of this genus. It is for this reason that recent authors now gener- 

 ally apply to the present species the name stawhylinus, proposed by Jurine, 

 though it is of somewhat later date, the name minutus being confined to another 

 species so named by Glaus. In every case the present species must be regarded 

 as the type of the genus Canthocamptus and at the same time as the type of the 

 whole family Canthocamptidce. 



Occurrence. This form is very common in the neighbourhood ofChristi- 

 ania, especially early in the spring, and in all probability is distributed over the 

 greater part of the country. It generally occurs in shallow ponds and ditches 

 together with other fresh-water Entomostraca, more rarely in larger lakes. Male 

 and female specimens occur with almost equal frequency, and are often found tied 

 together in copula, the female being grasped by the anterior antennae of the male 

 at the base of the caudal setae. The swimming movements of the animal are not 

 very rapid, and are effected in a somewhat reeling manner. It also moves with 

 great dexterity on the bottom, or along the leafs and stems of aquatic plants, by 

 curving and twisting its very flexible body, and applying its legs as levers. 



Distribution. British Isles, Sweden, Denmark, Central Europe, North 

 America, Novaja Zemlja. 



124. Canthocamptus minutus, Glaus. 



(PI. CXXVIII). 

 Canthocamptus minutus, Claus, Die freilebenden Copepoden, p. 22, PI. XII, fig. 1, PI. XIII, fig. 2. 



Syn: Canthocamptus lucidulus, Eehberg. 



Specific Characters. Female. Body slender and elongated, sublinear in 

 form, being of almost equal width throughout. Urosome with the segments less 

 sharply marked off than in the type species, genital segment scarcely longer than 

 the 2 succeeding ones combined, last segment without any dentiform projections 

 at the end outside, anal opercle somewhat less prominent and edged with about 

 12 spinules, which are all bifid at the end. Caudal rami scarcely as long as the 

 anal segment, and conspicuously thickened in the middle, the outer edge being 

 very convex and provided with 3 small denticles and 2 hair-like bristles, tip 

 somewhat exserted and obliquely truncated, apical setse rather slender, the inner- 

 most but one about twice as long as the adjacent seta on the outer side. An- 

 terior antennae much shorter than in C. staphylmus, otherwise of a very similar 

 structure. Posterior antennae and oral parts likewise of essentially the same structure 



26 Crustacea. 



