106 



45. Heteroeope saliens (Lilljeborg). 



(PI. LXXI & LXXII). 

 Diaptomus saliens, Lilljeborg. Ofvers. Vet. Akad. Forh. Vol. 19, p. 395, PI. 3, figs. 1831. 



Syn: Heteroeope robusta, G. O. Savs. 

 alpina, G. 0. Sars (immature). 



romana, Imhof. 



Specific Characters. Female. Body comparatively robust, with the anterior 

 division, seen dorsally, oblong oval in form, greatest width not attaining half the 

 length, and occurring about in the middle, anterior extremity abruptly contracted 

 and obtusely truncated at the tip, posterior slightly attenuated. Tiresome scarcely 

 attaining half the length of the anterior division, genital segment about the length 

 of the other 2 combined, and having the genital protuberance simple, without any 

 spines or appendages, anal segment shorter than the middle one. Caudal rami 

 about the length of the anal segment, and scarcely widening distally, each carrying 

 outside the ' 3 apical setse a small unciliated bristle, not attaining the length of 

 the ramus. Anterior antennae, when reflexed. reaching somewhat beyond the 2nd 

 caudal segment. Last pair of legs with the terminal joint considerably dilated, 

 lamellar, carrying outside 2 spinules, inside 4 distinctly bidentate denticles, 

 apical spine very long and coarsely denticulate in its distal part. 



Male of about the same size as the female, and not very different in shape, 

 though the urosome is comparatively more slender, and, as usual, 5-articulate. 

 Right anterior antenna with the middle section but slightly tumefied. Natatory 

 legs of same structure as in the female. Right last leg with the outer 2 joints 

 well defined, and together about the length of the antepenultimate one, the 

 latter without any protuberance of the inner edge; terminal joint of left leg 

 oblong oval in form, about 3 times as long as it is broad, and finely ciliated 

 inside, inner apical spine rather elongated. 



Colour. Body generally of a beautiful ultramarine hue, antennae, oral 

 parts and urosome often tinged with dark orange. 



Length of adult female about 3 mm. . 



Remarks. As stated above, this form was first described by Prof. Lillje- 

 borg as Diaptomus saliens, and the same form was somewhat later recorded by 

 the present author under the name of Heteroeope robusta, Prof. Lilljeborg's paper 

 being at that time unknown to him. The Heteroeope romana of Imhof is unque- 

 stionably the same species, and this is also the case with the form recorded by 

 the present author as H. alpina, which was only founded on immature specimens 

 of H. saliens. It may be regarded as the type of the present genus. 



