508 K. I. MARKS AND W. WESCHE 



the manner of a Xotommata ; indeed, it was at first thought to be 

 a young Proales petwrnyzon. A Literal vie^y enabled one observer 

 to obtain a glimpse of some membranes situated on the ventral 

 side of the brain, which are probably the remains of a digestive 

 system. 



Brachionus quadratus Rous. S , Fig. 1. 



Stoutly fusiform in shape, a lateral view shows the head 

 and foot curved downwards when swimming free. 



Head, inclined to be globular, a little variable in shape ; the 

 constriction of the neck also varies with position. The head is 

 capable of retraction within the body. 



Body, cylindrical, stout, has marks of the edge of the carapace, 

 as in Diaschiza. A fold of skin is sometimes seen in dorsal view. 



Foot, stout, short, and wrinkled, tapering from body and 

 retractile. 



Toes, minute, triangular; sometimes a thread is spun from 

 their extremities. 



Cilia, long. 



Brain, large, three-lobed on the front. Sometimes oval glands 

 seem to form part of it, in dorsal view. 



Eye, rather nebulous, not well defined, faintly red, and variable 

 in shape. 



Antennae : dorsal, well forward on the head ; lateral, low down 

 on sides of body, as in the female, with long setae. There 

 is no digestive system nor even remains visible. 



A vascular system is present, but the lateral canals are 

 difiicult to make out. Mr. Marks observed two flame-cells on 

 each side of the lateral canals. There are well-marked glands 

 to toes. 



• Generative system : a very large sperm-sac tapering from 

 the centre of the body cavity to the middle of the foot. It is con- 

 stricted as it passes through the end of the body, by which means 

 the spermatozoa seem contained ; but it is impossible to make 

 out the nature of the ejaculatory apparatus, on account of its 

 minute size. A dark granular mass contained in a vesicle shows 

 above the testis in dorsal view. 



Size, ^iyth to y|(^th inch (127 /x— 141 /x). 



Habitat, pond in Willesden Lane, March 8th and 21st, 1903. 



Besting eggs were seen carried by several females, and two 



