with a revision of the ZimnwidcB of Authors. 339 



formed of a number of lobes or tubes which are placed on the 

 inner side of the liver and extend a short distance beyond it. 

 into the apex of the spire. These are tilled with a greenish 

 substance consisting of nucleolated cells and ova in all >tages 

 of development which obtain previous to their extrusion. 



The penis is contained in a sac (preputium) which opens on 

 the side of the neck on a line with the tentacle and midway 

 between the left tentacle and the mantle margin. The organ 

 is short and stout, the retractor muscles were quite perceptible, 

 and a triangular appendage, perhaps equivalent to the flagel- 

 lum, was observed at the posterior end. The vas deferens is 

 slender and is nearly enclosed by the prostatic gland) which 

 is small and of an amber color. The epididymis is much con- 

 voluted and nearly as long as the vas deferens. The testicle is 

 long, and composed of numerous minute tubes with innumera- 

 ble ramifications. 



Respiratory system. The opening of the pulmonary cham- 

 ber is closed by a lobe of the mantle. The margin of the lat- 

 ter 'in some individuals is tuberculate (under a high power), 

 while in others nothing of the kind was observed. 



There was no perceptible cellular structure to the lung, but 

 the walls of the chamber are highly vascular, and it occupies, 

 when dilated, nearly half the last whorl. Myriads of a species 

 of cercaria were observed in the 'chamber, in some individuals. 



Special organs. The eyes are well developed. The choroid 

 was thickly covered with black pigment. A well marked vit- 

 reous humor was observed, and there appeared to be ;i r,-i/st<il- 

 linelens. The sclerotic coat is tough, and traversed by nume- 

 rous blood-vessels. Theeyeball is of an oval shape, and the 

 axes of the two eyes appeared to !><• somewhat divergent. 



The blind sac, described by Leidy, and which he suggests 

 may be the seat of the sense of .-null. i> quite evident.* It is 

 a minute linguiform Bac, reflected beneath the buccal mass. 



The auditory vesicle is close behind it, and is of an oval 



