ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 625 



sponding to this appearance, and in some cases a large number of 

 females may be seen to bo without it altogether. A more proper 

 term would be " ring " simply. 



It is not easy to detect when an Ophiurid is infested by these 

 parasites, but as a rule such specimens bave a more greyish tint, their 

 tissues appear softer, and tbeir movements are less rapid ; as a rule 

 one in twenty AmpMurce were found to contain Ortbonectids ; the 

 observation of Metsdmikof that a consequence of their presence is 

 an atrophy of the genital glands, has been verified by Julin. 



An adult male is ' 104 mm. long, the body fusiform and elongated, 

 and a little drawn out at either end, there are generally six rings, the 

 cilia on the first (head) are directed forwards, and on the rest back- 

 wards ; the spcrmatozoids are contained in a structureless pouch, and 

 when mature may be seen moving about rapidly within it ; when the 

 wall of the pouch bursts they escape between the muscular fibrils, which 

 separate from one another so as to form a cavity, bounded externally 

 by the ectoderm ; the cells of this layer undergo change and some 

 become detached, and the male products are then able to make their 

 way to the exterior ; at the same time it may be seen that the 

 muscular fibrils undergo atrophy. 



The cylindrical form of the female is - 280 mm. long, is fusiform 

 and has generally eight rings, the first and last of which are formed by 

 a large number of small ectodermic cells. The flattened form of female 

 is 0'250 mm. long, has wide ventral and dorsal surfaces, and narrower 

 sides, the grooves are so shallow that it is impossible to count the 

 number of the rings, and the whole surface is covered with cilia ; this 

 form was regarded by Metschnikof as being immature, but the 

 presence of ova is not in support of that view, which is more com- 

 pletely contradicted by the differences between its history and that of 

 the cylindrical form ; the flattened forms ajjpear to break up into 

 fragments, and the ova, instead of being free, are kept united together 

 to form more or less regular masses, limited externally by a ciliated 

 epithelial layer derived from the ectoderm of the adult. As has been 

 already stated, there is a difference of sex in the products of these two 

 female forms. As to the question of parthenogenesis, which is raised 

 by some observations, the author does not yet feel himself able to 

 speak confidently. 



New Rotifer (Cupelopagis bueinedax).* — Mr. S. A. Forbes de- 

 scribes a new Rotifer as follows : — 



Ciqwlopagis gen. nov. Footless, eyeless, without carapace, and 

 totally destitute of cilia or other vibratile structures, or locomotor 

 organs of any kind. The trochal disk has the form of a large, 

 oblique cup, which can be either retracted wholly, or pushed up by a 

 constriction of its wide mouth. In the bottom of this cup is the oral 

 aperture, which opens into a very large, loose crop, at the bottom of 

 which, and usually behind the middle of the body, is the mastax. 

 The jaws, which project into the crop, are composed of two sharp, 

 slender hooks, with about four slender, straight teeth at the inner base. 



* Amor. Mon. Micr. Journ., iii. (1882) pp. 102-3 (1 fig.). 



