398 History of the Hairy -backed Animalcules. 



character which is more marked in the following species, and 

 more strongly still in the genus Dasydytes. The upper surface 

 of the body is conspicuously studded with quincuncial dots, the 

 optical effect of what I judge to be tubercles or warts so 

 arranged, from which, perhaps, the hairs spring. (In the en- 

 graving I have not indicated this reticulation, that I might dis- 

 play more clearly some important particulars of the internal 

 anatomy.) The back and sides are clothed with very fine hair of 

 only moderate length, which is directed backwards. I did not 

 detect any trace of facial vibrissas. 



The mouth is rather larger than usual, abruptly narrowed 

 behind. The oesophagus is of the normal form, a cylinder with 

 very thick transparent walls, centrally pierced by a slender 

 tube. I was surprised to observe that the oesophagus didjaot 

 embrace the mouth, but appeared to commence just behind it, 

 by a peculiarity of structure not easy to explain (perhaps a 

 sudden dip or angle carrying it out of focus, though in incessant 

 manipulation, such a circumstance could scarcely have been 

 undetected), apparently with a depressed centre, where the 

 medial perforation began. (See Fig. 7.) Imbedded in the exterior 

 wall of this viscus, on each side of its summit, was a minute 

 oval dot, well defined, which at times appeared to have positive 

 colour, and winch reminded me of the eye-specks of Rotifera. 

 At the posterior extremity of this perforated viscus (which 

 in ignorance we call the oesophagus), about one-fourth of its 

 length, having a vaulted figure, seemed separated by a delicate 

 bounding line from the rest. The posterior extremity was 

 slightly excavated, and seated upon the correspondingly convex 

 summit of the intestine, — another deviation from the normal 

 condition, in which the intestine embraces the oesophagus in a 

 hollow. On each side of the summit of the intestine an oval 

 clear vesicle was seated, having the appearance, situation, and 

 doubtless function, of those glands which, in almost all Rotifera, 

 we assume to be pancreatic. 



But Hit: most interesting result of examination was the in- 

 dubitable discovery of a water-system on the plan of that of the 

 Rotifera. Serpentine vessels ran along each side of the body- 

 cavity (two visible on one side, one only on the other), which 

 could be traced very distinctly (especially when the animal 

 bent itself laterally) nearly to the fork, and in front to tho 

 occiput, where each ended in a clavate bulb. Immediately in 

 front, of this pair of bulbs, but not having any visible connection 

 with them, were two globular vesicles, which refracted the 

 light strongly t and were probably filled with some fluid. These 

 were not distinct in the same locus that defined the minute 

 eye-like specks, and hence must have been in the opposito 

 (ventral) region of the head-cavity. After a while, one only of 



