ZOOLOGY AND BOTANY, MICKOSGOPY, ETC. 215 



characters. Doubt was thrown upon these observations, but Dr. J. 

 Leidy has recently * added to the list of non-ciliated rotifers, and 

 brought together the scattered information upon the subject. In 

 1857,t Dr. Leidy described a rotifer-like creature quite different from 

 those before mentioned, and having a large protractile pouch or cap 

 in lieu of the usual rotary disks. This he named Bictyophora vorax. 

 Still another species (Apsilus lentiformis) was described by Meczni- 

 chowin 1866 ; and another (Balatro calvus), parasitic upon worms, was 

 observed by Claparede in 1867. In 1882 Mr. S. A. Forbes described 

 a form which Dr. Leidy suspects to be identical with Dictyophora vorax. 

 The last discovery of Dr. Leidy is a rotifer in which a sort of 

 head, in the form of a cup prolonged at the mouth into an incurved 

 beak, takes the place of the rotary disk of ordinary rotifers. This 

 creature, which is named Acyclus inquietus, was found occupying a 

 central position among a group of the rotifer Megalotrocha alba, both 

 parasitic upon a Plumatella, This species is considered by Dr. Hudson, 

 ante, p. 161. 



Echinodermata. 



Supposed Coral-eating Habits of Holothurians.l — Mr. W. S. 



Kent, from a study of Gucumaris communis and C. pentactes, is able 

 to say that the Holothurians do not subsist on living coral. The 

 oral tentacula in both these species are largely developed, taking the 

 form of ten extensively ramifying pedunculate plumose or dendriform 

 tufts, stationed at equal distances around the oral opening. It is 

 with these organs that the food substances are seized and conveyed to 

 the alimentary system, though in a manner totally distinct from what 

 obtains in other tentaculiferous animals, such as a sea-anemone, 

 tubicolous annelid, or cuttle-fish. When on the full feed, it was 

 observed indeed that the tentacles of the Holothurian were in constant 

 motion, each separate dentritic plume in turn, after a brief extension, 

 being distally inverted and thrust bodily near to its base into the 

 cavity of the pharynx, bearing along with it such fragments of sand 

 and shelly matter as it had succeeded in laying hold of. No con- 

 seciitive order was followed in the inversion of the separate tentacles, 

 that which at the moment had secured the most appetizing morsel 

 gaining seemingly the earliest entree. But little time was lost 

 in this feeding process, for no sooner was one tentacle everted than 

 another was thrust into the gullet, and so the meal continued, as not 

 unfrequently observed, for several hours together. To furnish a fitting 

 simile for this anomalous phenomenon of ingestion, one might imagine 

 a child provided with ten arms, after the manner of ancient Buddha, 

 grasping its food with every hand, and thrusting it in a quick and 

 continuous stream down its throat, the hands and arms with every 

 successive mouthful not stopping at the mouth but disappearing up to 

 or above the elbow withia the visceral cavity. 



* Proc. Acad. Nat. Sci. Philad., 1882, pp. 2i3-50 (1 pL). Amer. Natural, 

 xvii. (1883) pp. 212-3. 



t Proc. Acad. Nat. Sci. Philad., 1857, p. 204. 

 X Nature, xxvii. (1883) .p 433. 



