378 EEV. A. H. NOEMAN AND ME. G. S. BEADT 



above and below well rounded off ; no teeth at the infero-posteal 

 angle; ventral margin straight, fringed with cilia; surface faintly 

 longitudinally striate and (occasionally) reticulate. Head nearly 

 erect, large, with a blunt, widely-rounded, hood-formed rostrum, 

 which does not project beyond the ventral margin of the carapace; 

 anterior antennas considerably shorter than the hood; posterior an- 

 tennae short, one branch furnished with three, the other with five 

 setae. Eye-spot large, two-thirds the size of the eye, and nearer 

 to the eye than to the extremity of the rostrum. Abdomen short 

 and broad, and having the distal extremity truncate ; its superior 

 margin gently arched ; supero-posteal angle distinct but rounded 

 off ; marginal spines, from fifteen to twenty, of nearly equal size, 

 but increasing slightly in length from before backwards, one or 

 two spines usually smaller than the others round the supero-pos- 

 teal angle ; a single obtuse process situated midway between the 

 most anterior of the marginal spines and the origin of the abdo- 

 minal setae ; terminal claws large, gently curved, and having a 

 large secondary process springing from near their base, and more 

 than one-third the length of the claw itself ; there is also a tuft 

 of very fine hairs at the origin of the claws. Length, aVth of 

 an inch. 



Common throughout northern Europe* in lakes, ponds, canals, 

 and slowly running streams. 



The original description of the species by Miiller, in the " Zoo- 

 logics Banicce Pro&romus" is merely " cauda inflexa, testa sub- 

 quadrangulari." Erom these words it is impossible to determine 

 which of several species was intended. The figures given sub- 

 sequently by the same author, in his work on the Entomostraca 

 (pi. IX, figs. 1-3), are likewise insufficient for the purpose of 

 identification. The form given to the abdomen certainly seems 

 to give ground for the conclusion of G. 0. Sars, that his Lynceus 

 tenuicaudis is the species which Midler intended to represent. 

 However, it is impossible to decide that point with certainty, 

 and we follow therefore the rule which is generally observed in 



* The Freshwater Entomostraca of the south of Europe have as yet been almost wholly 

 neglected. Lynceus quaclrangnlaris is not among the species found by Jurine in the neigh- 

 bourhood of Geneva. 



