202 Mr. P. H. Gosse on the British Rotifera, 



Family Philodin^a. 



Callidina bidens. Body spindle-shaped : jaws furnished with 

 two distinct teeth. Length ^^'yth inch. Perhaps this is no other 

 than Prof. Ehrenberg's C. elegans, of which he describes the jaws 

 as having many delicate teeth. I have, however, examined nu- 

 merous specimens, and have always found them distinctly two- 

 toothed. 



Rotifer vulgaris. 



R. citrinus. 



R. macrurus. 



R. macroceros. Wheels large ; antennal process (the " respi- 

 ratory tube " of Prof. Ehrenberg) veiy long and mobile. Length 

 y^^th inch. 



Philodina roseola. 



P. citrina. 



P. aculeata. 



P. megalotrocha. 



Family Brachion^a. 



Noteus quadricornis. 



Anurcea curvicomis. 



A. fissa. Lorica smooth, hyaline, swollen at the sides and at 

 the back ; flattish on the belly ; truncate in front, without any 

 spines, attenuated and truncate posteriorly. There is a deep fold 

 running down each side, or else the ventral plate is distinct from 

 the dorsal ; the ventral is also cleft through its medial line. Eye 

 very large, pale. Length 2^0^^ inch. 



A. tecta. Nearly agrees in form with A. curvicomis, but the 

 posterior extremity is rather more pointed, and the tessellations 

 are different; being larger and arranged on each side of a 

 mesial dorsal ridge, which gives to the back the form of a vaidted 

 roof. Length 2^0*^ inch. 



A. acuminata. 



A. aculeata. 



A. brevispina. Nearly agrees with A. aculeata, but the posterior 

 spines are very short ; the frontal spines are much less curved 

 forwards; the surface is not punctated; and it is colourless. 

 Length xi^^h inch. 



A, cochlearis. Lorica spoon-shaped ; with six spines in front ; 

 the medial pair curving strongly forwards : posterior extremity 

 attenuated into a long slender spine, inclined forwards : back 

 ridged and tessellated as in A. tecta. 



A. serrulata. 

 Brachionus pala. 



B. oon. Lorica ovate, the back swelling with an uniform curve, 

 by which it is distinguished from B. pala, which is truncate or 



