55 



short and blunt at the tip. Urosome rather narrow, almost linear in form, with 

 the segments finely spinulose at the hind edges. Caudal rami somewhat longer 

 than they are broad, apical setse rather slender, the innermost but one more than 

 twice as long as the urosome. Anterior antennae somewhat exceeding half the 

 length of the cephalic segment, 9-articulate, the proximal joints comparatively 

 thick and robust, terminal part rather slender. Outer ramus of posterior antennae 

 with the 1st joint longer than the other 3 combined. Anterior maxillipeds com- 

 paratively broad; posterior ones with the hand oblong quadrangular in form, palm 

 not defined, dactylus strong and curved. First pair of legs rather strongly built, 

 outer ramus with the 1st joint about the length of the other 2 combined; last 

 joint armed with 5 very sharp and smooth claws and 2 setse; inner ramus with 

 the outer 2 joints imperfectly defined, and carrying on the tip a strong claw-like 

 spine. Last pair of legs with the inner expansion of the proximal joint very large, 

 extending somewhat beyond the distal joint, and armed with 5 slender spines, one 

 of which is very long; distal joint oval in form, with 5 similar spines. Ovisac 

 very large. 



Male about the same size as the female, but having the posterior division 

 of the body considerably narrower. Anterior antenna? very strong, hand nearly 

 globose, dactylus simple, claw-shaped. Inner ramus of 2nd pair of legs with the 

 middle joint considerably expanded, outer projection smooth, inner somewhat 

 longer, and densely hairy in its outer part. Last pair of legs very small, prox- 

 imal joint but very slightly expanded inside, and provided with a solitary seta, 

 distal joint oval, with 4 spiniform setae. 



Colour dark yellow or orange. 



Length of adult female 1.20 mm. 



Remarks. This form was first described by Prof. Lilljeborg, who, how- 

 ever, erroneously identified it with Cyclops chelifer of 0. Fr. Miiller. It was 

 some years afterwards recorded by Seb. Fischer as Harpacticus full-its, and the 

 specific name proposed by that author ought accordingly to be retained and pre- 

 ferred to those given to the species by Boeck and Norman, which are of 

 later date. 



Occurrence. This form is found along the whole Norwegian coast, and 

 often in great abundance, in small rock-pools at, or more generally somewhat 

 above, high-water-mark. The water in these pools is more or less brackish and 

 often exhibits a very high temperature by long exposure to the sun. I have also 

 occasionally found this form in perfectly fresh water, but in no cases at any great 

 distance from the shore, and it is reasonable, therefore, to assume that at times 



