for the Microscope. 103 



posterior spines. No eyes. Double wheel. In stagnant 

 water, with decayed leaves. (PI. X., fig. 15.) 



824. SMOOTH BRACK IONUS (Brachiomis iincolaris). 

 Lorica smooth, compressed, with six short spines in front, 

 rounded behind. One eye. Foot forked. (Pi. X., fig. 25.) 



825. ROUGH BRACK IONUS (Brachiomis Bakeri). Lorica 

 rough and tesselated, with six unequal teeth in front, and 

 two posterior spines. Foot forked. (PI. X., fig. 24.) 



826. ROUND PTERODINA (Pterodina patina). Round 

 or oval. Lorica thin and transparent. Eyes two. Foot 

 simple. Amongst duckweed. 



827. WATER-BEARS (Tardigrada). Curious little eight- 

 footed animals, crawling slowly, like miniature bears, about 

 water- weeds, in company with Rotifers, though not belong- 

 ing to them. 



The following are Crustaceans belonging to the division 

 called ENTOMOSTRACA. 



828. FAIRY SHRIMP (Chirocephahts diaphanus). An 

 inch in length, nearly transparent, with a pinkish tinge. 

 In pools. 



829. BRINE SHRIMP (Artemia salina). About half an 

 inch long. In salt-pans. 



830. COMMON WATER-FLEA (Daphnia pulex). The 

 most common of water-fleas. Shell oval, with a sharp 

 serrated spine at the base. In ponds and ditches. (PI. 

 XL, fig. 6.) 



831. GREAT WATER-FLEA (Daphnia Schafferi). The 

 largest of British species. Shell nearly circular, with a 

 sharp basal spine. Surface reticulated. Ponds. Autumn. 



832. SPINELESS WATER-FLEA (Daphnia vetula}. Shell 

 ovate, and smaller that the foregoing, without a basal 

 spine. The surface striated. Ponds and ditches. 



833. SPURRED WATER-FLEA (Daphnia mucronata}. 

 Front edge of shell straight, ending below in a sharp 

 spine. Ponds. June to October. (PI. XL, fig. 7.) 



834. ELEPHANT WATER-FLEA (Bosmina lotigirostris). 

 Shell oval, rounded behind, terminating in a basal spine. 

 Upper antennas large, curved, cylindrical, and many- 

 jointed. In ponds. (PI. XL, fig. 14.) 



