420 On Two new Species of Monhystera. 



The mouth is minute, and is surrounded, as in the other 

 case, by six exceedingly slight cuticular elevations, each 

 bearing a very small papilla. The papillse, however, are not 

 setose, but conical. The mouth-cavity is much larger in this 

 species, and is of oblong shape. Its walls are strengthened 

 by four longitudinal chitinous rods of peculiar shape 

 (tig. 5, CL). 



The bulb of the oesophagus (fig. 4, B.) is smaller, and of 

 a somewhat different shape from that of M. ivilsoni. It is 

 more oblong than pyriform, and nearly parallel-sided, except 

 at its anterior end, which is conical. A pair of large granular 

 cells is present at the sides of the bulb, near its junction 

 with the oesophagus, as was observed to be the case in the 

 preceding species. The granules contained in the large cells 

 of the chyle-intestine are of a paler colour than in M, ivi/soni, 

 this character affording one of the readiest means of dis- 

 tinguishing the species. 



In the female the vulva is situated much nearer to the 

 anus, as is shown at a glance by the values given for & at 

 the beginning ot the descriptions. The distance between 

 anus and vulva is, in fact, almost equal to the length of the 

 tail. The number of eggs usually found in the uterus in 

 mature forms is much greater than in M. wilsonu There 

 may be from 16 to 20, and their development, though 

 apparently more gradual, appears to take place more simulta- 

 neously, a considerable number of embryos being at about 

 the same stage, instead of developing one at a time. 



Finally, all the embryos appear to rupture their egg- 

 membranes, and lie stretched out nearly straight within the 

 uterus. This condition was never observed in M. wilsoni. 

 It is possible that they do not escape until the death or 

 rupture of the parent. 



Two examples, having mouth-parts and most of the other 

 organs precisely similar to those of the females, were found 

 to contain both male and female reproductive organs (fig. 4). 

 In both cases there were spicules and an ovary, and there 

 also appeared to be a functional testis ; but in neither were 

 any feitilized ova seen, nor was there any trace of a vulva. 

 It seems probable that the species is a protandrous herma- 

 phrodite, the same individual which functions at first as a 

 male subsequently losing its spicules and other evidences of 

 male nature, and becoming purely female. Presumably a 

 vulva is developed at this period, and the worm becomes 

 capable of being impregnated by another individual. 



Jn the hermaphrodite examples there appear to be two 

 excessively fine spicules and a chitinous accessory piece 



