101 



elongated; caudal rami equalling in length the last 2 segments combined, and 

 having the apical setse more elongated than in female. Right anterior antenna 

 rather strongly built, with the middle section considerably tumefied. Last pair 

 of legs with the 2nd joint but slightly dilated, terminal joint of both legs exhi- 

 biting a slight median subdivision, that of left leg terminating in 2 obtuse lobes. 



Colour. Body more or less pellucid, in some cases, however, tinged with 

 yellowish brown. 



Length of adult female reaching to 2.20 mm., that of male to 1.85 mm. 



Remarks. This form was first described (in the year 1853) by Seb. 

 Fischer under the name of Cyclopsina lacinulata, being regarded as identical with 

 0. FV. Muller's Cyclops lacinulatus, which, however, is evidently a very different 

 form, and is probably referable to Diaptomus castor Jurine. The same species 

 was subsequently observed by Prof. Lilljeborg, who described it as a new species 

 of the genus Temora (T. velox). It is, however, only the female that is referable 

 to the present species, whereas the male described by Prof. Lilljeborg belongs 

 to another nearly-allied species, to be described farther on. The Temora Clausii 

 of Hoek is unquestionably the present form. It is the largest of the known 

 species, and moreover easily recognizable, at any rate in the female sex, by the 

 peculiar form of the lateral expansions of the last segment of the metasome, as 

 also by the less elongated caudal rami. 



Occurrence. I have found this form rather abundantly in small pools on 

 2 islands lying off Arendal. The pools were located at only a short distance 

 from the shore, and it is very probable therefore that at times the water is 

 mingled with sea-spray. This is evident from the circumstance that in the same 

 pools the well-known Harpacticid, Tigriopus fulvus Fischer, occurred very plenti- 

 fully. I have, however, met with this Calanoid also in perfectly fresh water, 

 for instance in the Vansj0 at Moss, and in tranquil creeks of the river Glommen 

 (at Nipen), many miles from its mouth. The specimens in these places, however, 

 were of far inferior size to those found in the brackish pools, and also much 

 more pellucid. The animal moves very rapidly in abrupt bounds, and thus fully 

 deserves the specific name given to the species by Prof. Lilljeborg. 



Distribution. Russia (Fischer), Germany (Schmeil), Britany (Brady), 

 France (Richard), Holland (Hoek), Skane (Lilljeborg), the Baltic (Nordqvist), 

 fresh-water estuaries of the Caspian Sea (the present author) 



