The Fresh-water Entomostraca of Cape Province. 309 



5. DAPHNIA THOMSONI, Gr. O. Sars. 

 (Plate XXX, figs. 2, 2 a-c.) 



Dciph/tia thomsoni, Gr. O. Sars. Contributions to the knowledge of 

 the Fresh-water Entomostraca of New Zealand. Chr. Vid. Selsk. 

 Skrifter f. 1894, p. 5, pi. i. 



Si/n.: Daphnlu similis Thomson (not Claus). 



Specific Characters Female. Carapace, seen laterally, broadly oval 

 in outline, with the spine rather thin and obliquely upturned, originat- 

 ing somewhat above the axis of the body. Head comparatively large 

 and distinctly carinated throughout, being defined above from the cara- 

 pace by a slight concavity of the dorsal margin, frontal part evenly 

 rounded off, inferior edge straight and produced behind to a rather 

 prominent acuminate rostrum. Dorsal denticles of carapace not ex- 

 tending beyond the cervical region. Eye of moderate size. Autennulse 

 extremely small, scarcely projecting beyond the hind edge of the head 

 except with the apical papillse. Tail-piece rather produced and tapering 

 distally, with the hind edge somewhat flexuous, exhibiting below the 

 anal fissure a slight sinus ; anal denticles well developed, twelve to 

 fourteen in number on each side ; apical claws slender and evenly 

 curved, with the secondary denticles well marked. 



Body highly pellucid, with a faint yellowish or pale reddish tinge. 



Length of shell (without the spine) reaching 3 - 7 mm. 



Renun-1;*. This form was first recorded by Prof . Thomson from New 

 Zealand under the name of D. similis ; but as that name had been 

 previously given by Claus to another species, it was changed by the 

 present author to D. thomsoni. Its nearest ally is unquestionably the 

 Australian species D. cariafa,Kiug, and not, as believed by Dr. Richard, 

 D. similis, Claus. From the numerous varieties of the former species 

 it is easily distinguished by the rather different shape of the tail-piece, 

 which somewhat resembles that in D. magua. 



Occurrence. The present species, which has been fully described and 

 figured in my paper on the New Zealand Entomostraca, was also reared 

 in the year 1895 from the Knysna mud, and some specimens of the 

 earlier generations were at that time secured and preserved for further 

 examination and comparison. The figures given on the accompanying 

 plate have been drawn from one of these specimens. 



Distribution. New Zealand. 



6. DAPHNIA PROPINQUA, Gr. 0. Sars. 



(Plate XXXI, figs. 1, 1 , 6.) 

 Daphnia propingua, Gr. O. Sars. On some South African Eiito- 



