1910.] ORGANS OF THE FISH CHIMERA MONSTROSA. 525 



Mullerian Ducts. 



At this stage the ducts of M tiller surpass in diameter the sperm- 

 ducts, and appear as tubes running in the peritoneum along the 

 outer border of each half of the kidney, then between the testes 

 and coiled sperm-ducts to meet anteriorly in the middle line, and 

 open by a common aperture into the coelom. Their lining is 

 thrown into folds in some regions. 



Abdominal pores, situated at the posterior margin of the anus, 

 are both present and open. 



Adult Female Chim^eua moxstrosa. 



In the adult condition the female Ghimcera is somewhat larger 

 than the male in size and general proportions. In all external 

 characters (except in the absence of claspers) the female resembles 

 tbe male, but differs from it in the possession of a longitudinal 

 shallow groove in the ventral middle line of the body, a little 

 distance behind the urogenital openings. This fleshy groove is 

 bordered by skin white in appearance ; it is lined with elongated 

 glandular cells, extends for a distance of from 2| to 34 inches, 

 and is nearly |- inch deep. The urogenital organs — just as in the 

 male — extend the whole length of the abdominal cavity and 

 consist of two ovaries, two oviducts with shell-glands, kidney 

 (paired and unpaired regions) with ureters and urinary bladder, 

 and lastly, a median so-called " receptaculum seminis." 



Genital Organs. 



The two ovaries are situated one on each side of the dorsal 

 middle line of the abdominal cavity, suspended by the mesovarium, 

 and situated anterior to the front end of the kidney. Irregular 

 in outline and easily ruptured, they present a lobulated appearance 

 due to the Graafian follicles, some of which are very large 

 (text-fig. 50). 



The oviducts are extremely prominent tubes differentiated into 

 regions, opening anteriorly on the posterior aspect of the peri- 

 cardial wall and in front of the liver by a single large median 

 coelomic opening, by which the eggs liberated from the ovaries 

 gain access to the oviducts. For the first one -third or one 

 quarter of their length the oviducts are of comparatively small 

 diameter, but then rapidly increase to form the shell-glands. 

 These almost spherical structures are external to and at the leA^el 

 of the ovaries, and are lined by long glandular epithelial cells 

 which are elevated to form a circular ridge on the inner surface of 

 the wall ; this ridge in a fresh specimen appears white against 

 the rest of the wall of the gland. 



The succeeding quarter of the oviduct resembles the first quarter 

 in diameter, after which the oviduct gradually increases in width ; 



