400 History of the Hairy -backed Animalcules. 



Sp. 8. D. goniathrix {Gosse). (PL ii. Figs. 9—12.) Hairs 

 long, each hair bent with an abrupt angle ; neck much 

 constricted. 



This and the following species I briefly defined, and 

 formed of them the genus Dasydytes, in the Annals of Natural 

 History, for Sept. 1851. The present very remarkable form 

 was obtained from a pool at Leamington, in July of the pre- 

 ceding year. The length of the body is 1-1 50th of an inch ; 

 measured to the tips of the bristles, 1-1 10th. The head is 

 nearly circular, as wide as the body, without lobes, but ab- 

 ruptly separated from a slender neck. The mouth takes the 

 form of a permanently projecting truncate lip, or short tube. 

 The body is rather slender, swelling toward the hinder part, 

 and tapering to a rounded or truncate point, without any trace 

 of the ordinary forked foot. A most peculiar and bizarre cha- 

 racter is imparted to the creature by its clothing of very long 

 bristles, set along each side of the back, pointing obliquely 

 backward, but apparently wanting along the mesial line, which 

 rises into a ridge. Each bristle is bent near its tip at an 

 abrupt angle (see Fig. 12), so that it looks as if it had been 

 broken and mended. The front of the head is furnished with 

 long delicate hairs, not geniculate, which form two pencils 

 directed backward, ono falling on each side. Strong and con- 

 spicuous vortical currents were produced on each side of the 

 head, like those of the true Rotifera (Fig. 9), and in one speci- 

 men I distinctly saw that they were caused by these frontal 

 pencils of hairs, and that these were very long vibratory cilia. 

 The ventral surface is set with short fine hair, which becomes 

 longer behind (Fig. 10); doubtless cilia of unusual develop- 

 ment, for they produced strong longitudinal backward cur- 

 rents, continued from the frontal vortices. 



The tube of the oesophagus is always distinct, but the walls 

 are to be discerned only when the animal is flattened by the 

 coiiipressorium. Then it is seen to be fusiform, instead of 

 cylindrical, extending through one-third of the body, whore its 

 tube enters a wide cylindrical intestine, with a broad abruptly 

 truncate anterior extremity ; of this a short portion is clear, 

 when the remainder is occupied with opaque granular food, 

 and possibly may represent a, pancreatic gland of abnormal 

 form, as it embraces the hinder part of the gullet tube, or else 

 is perforate with a similar tube (see Fig. 9). But in one speci- 

 i this very portion was intensely opaque, while the intes- 

 tine was granular. The cloaca! orifice seems to be at the 

 very extremity of the hod)-, as no termination of the intestine, 

 aor even any dimimif ion of its diameter, can he discerned short 



of that point. On repeated occasions I have Been the act of 



defecation, in ono of which an oval clear corpuscle was dis- 



