402 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. 46. 



back by the ribbon-shaped ovary. The contractile vesicle is normal; 

 the excretory canals have each five flame-cells. 



The ganglion is a large triangular mass lying over the mastax and 

 extends nearly the entire width of the head. At the posterior angle 

 a granular, opaque deposit is usually found; this is no doubt the 

 retrocerebral sac, although it can not be stained intra-vitam. 



At the point of attachment of the four dorsal longitudinal muscles 

 small tufts of sensory setae are present. The animal is carnivorous ; 

 its food seems to consist principally of the smaller Bdelloids and 

 Gonochilus, whose trophi are often found in its stomach. When 

 swimming, the frontal part of the head is withdrawn and puckered up, 

 so that the animal appears squarely truncate in front. 



As this species does not have any close relatives among known 

 genera of Rotatoria, it has been made the type of a new genus; its 

 affinities seem to be with Synchsda and Ploesoma, but it is a parallel, 

 rather than an intermediate, branch of the Ploima. 



Total length, 320 /z; trophi, 62/i. 



Sphyrias lofuana inhabits weedy ponds; it was first found in the 

 old Fish Ponds, now filled in, and a few specimens occurred in the 

 swamps at Four Mile Run ; it is not uncommon in the ponds at Ken- 

 ilworth. From the list of species accompanying the original descrip- 

 tion it is evident that its presence in the Lofu River is adventitious; 

 all the species are pond forms and not one of the 22 is normally a 

 river planktont. 



ASPLANCHNOPUS HYALINUS, new species. 

 Plate 38, figs. 3 and 4. 



The body of this species is moderately elongate, the posterior, 

 globose portion being separated from the head by a very slight con- 

 striction or neck. The foot is nearly one-third as long as the body 

 and jointed, the terminal joint being about twice as long as the basal. 

 The toes are somewhat blade-shaped and approximately the same 

 length as the first foot-joint; the mucus glands are as long as the 

 entire foot. 



The corona is terminal and of the usual Asplanchna-tyYie; a 

 circumapical band interrupted ventrally at the mouth and laterally 

 by two small papillae bearing red pigment-spots. The ciUation of the 

 buccal field is limited to a line of short cilia on each side of the mouth, 

 passing from there transversely to the two lateral papillee. The dor- 

 sal antennae are not far posterior to the corona; there are two distinct 

 tufts of setae, united internally by the usual muscle; two nerve- 

 threads pass to the ganglion. The lateral antennae are in the usual 

 position. The gangUon has a prominent eyespot at its posterior end. 

 The retrocerebral sac is well developed, as well as the subcerebral 

 glands, these being about half as long as the sac. 



