OR OSSEOUS SYSTEM. 2/ 



water, is represented in Fig. 1 1, where we perceive seventeen 

 muscular lobes, a, a, for the movement of the vibratile cilia,/; 

 disposed around the mouth. The muscular apparatus b, of 

 the maxillae and the mouth are retracted by longitudinal 

 muscles c, which pass obliquely backwards, and the whole 

 body is forcibly retracted towards the fixed caudal extremity 

 by several longitudinal bands d, of muscular fibres which 

 extend the whole length of the body. The large central or 

 supra-eesophageal ganglion o, is accompanied by four other 

 ganglia, disposed around the oesophagus, and abdominal 

 nervous filaments p, are perceptible, extending longitudinally 

 on the inferior surface, as in other articulated classes. The 

 muscular apparatus of the jaws may almost be regarded as 

 analogous to the muscular stomach armed with teeth com- 

 mon in Crustacea. The narrow part of the intestine considered 

 as the oesophagus g, leads to a long and capacious digestive 

 cavity, which in many of the genera of rotifera developes nu- 

 merous caecal appendices, like the biliary follicles of annelides. 

 In this capacious intestine, extending from ^, considered as the 

 oesophagus to near the anus, i, on the dorsal part, we observe 

 small animalcules, naviculce, h, which have been swallowed 

 entire. The longitudinal dorsal vessel e, more like an 

 abdominal nerve, as in other articulata, follows the median 

 line, and gives off numerous lateral branches in its course. 

 Two glandular sacs /, appear to pour their secretions into 

 the muscular cavity of the mouth, as the liver into the 

 muscular stomach of Crustacea, or the salivary sacs into 

 the oesophagus of mollusca. The two ovaria m, form large 

 lobed organs extending upwards on each side of the intestine, 

 and open by one orifice into the cloaca, behind the rectum , 

 and two long narrow glandular sacs k, k, considered as testes, 

 pour their secretions into a large membranous vesicle 

 situate behind the cloaca. The jaws of this FIG. 

 animal are represented apart from the body, 

 along with their enveloping muscular apparatus, 

 in Fig. 12, where 1, , shows the serrated edges 

 of the numerous teeth on each side of the open- 

 ing of the mouth, 1, #, the muscular apparatus 

 of the jaws, and 1, c, the general muscular sac 

 of the mouth. One of the jaws is represented 

 at 2, Fig. 12, separated from the muscular sac 



