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a little behind the middle of the body; the ovaries do not reach 
far; the postvaginal part does not reach the middle between the 
vulva and the anus; the antevaginal part about a third of the 
distance to the proximal end of the oesophagus. Usually are found 
two eggs in the uterus, sometimes I have observed more, up to four. 
The cells of the intestine are filled with oil-globules. The tail 
is conical and pointed and always highly bent inwards, towards 
the vent, getting the shape of a hook. 
The male is inconspicuously more slender than the female and 
increases from the point where the masculine papillæ commence, in 
the way that the animal assumes its greatest circumference at 
the anus. The bursal musculature is highly developed and the 
numerous papillæ which are very prominent appear to have a lateral 
position, forming two longitudinal rows between which the body of 
the animal appears to be groove-shaped. The spicules are angular 
and provided with a longitudinal list in their distal half; an ac- 
cessory piece of a characteristical shape much resembling that of 
M. tridentatus figured by de Man in 1876, T. XIII, fg. 50. 
There is no doubt, that the form here described is closely related 
to the M. papillatus, especially as a more thorough examination has 
proved, that the M. papillatus is also provided with a serrated 
list opposite to the dorsal tooth. The principal deviations between 
the two forms are the following: 1) the difference of dimensions, 
2) the position of the vulva which in M. spectabilis is situated a 
little behind the middle of the body, in M. papillatus at the be- 
ginning of the last third part of the animal; 3) the length of the 
tail, which is more considerable in M. papillatus and finally the 
fact, that the male of the M. papillatus is unknown, while the 
male of the M. spectabilis is about as numerous as the female. 
If the two forms should prove to be identical it must be 
supposed that an alternation of generations takes place such as de 
Man supposes with Trilobus, but for the present I find it most cor- 
rect to consider the MM. spectabilis as specifically different from 
M. papillatus. 
