Cotylogaster occidentalis n. sp. gQ5 



])rove to 1)0 oiily highly developed niaiginal seiise orgaiis lioniologous 

 with thüSü of other Asi)id()bothnds aiid cai)able of Protrusion and 

 rctraction in a nianner siniilar to those which I have described. 



The Chief organs of the reproductive system, ovary, testes, vitel- 

 hiria and shell gland lie ventral to the inner musculatur tiibe and in 

 a general way resemble those of C. michnelis with the right and left 

 rehitions reversed. The ovary has nearly the form of a prolate 

 spheroid with its longer axis longitudinal. It lies at the right of a 

 median plane, nearer the dorsal surface, over a point about one third 

 the length of the ventral shield back from its anterior edge. It is, 

 in the specimens studied, a very little smaller than the testes, the 

 longer axis measuring nearly 0.5 mm. The shorter axes are a little 

 more than half as long as the major. The relations of the ovary and 

 the complex of organs in intimate relation with it are expressed 

 somewhat diagrammatically in Fig. 16. The oviduct arises from the 

 left (mesial) side near the posterior end and extends forward along 

 the side of the ovary, arching to the right across its anterior end, 

 Then after giving off Laurer's canal it turns rather sharply to the 

 left toward the shell gland. From the mouth of Laurer's canal to 

 the Shell gland the tube is ciliated but no cilia are discernible be- 

 tween the ovary and the opening of Laurer's canal. Projections of 

 the wall of the duct are present however in this portion extending 

 obliquely into the lumen at short intervals with their free edges directed 

 away from the ovary. They give in longitudinal sections of the duct 

 an appearance suggestive of the spiral value in the intestine of the 

 selachian. From 12 — 15 of these projections are present on each 

 side, as seen in longitudinal section, those from the opposite sides 

 appearing to be neither strictly opposite nor definitely alternate in 

 Position. 



This modification of the proximal part of the oviduct probably 

 corresponds essentially with that described by Voeltzkow ('88) and 

 Stafford ('96) in Aspidogaster. Prof. Osborn informs me that he 

 has observed the same condition in Cotylas^ns. These three are how- 

 ever the only members of the family in which it has been reported, 

 Laurer's canal communicates with the oviduct by a narrow opening 

 but at once widens out into a rather broad cavity filled in my longi- 

 tudinal series with an aggregation of spermatozoa. It follows the dorsal 

 surface of the ovary backward becoming narrower posteriorly and 

 opposite the hinder end of the ovary is deflected ventrally into line 

 with the major axis of that organ. From this point it continues caudad 



