MOLLUSCA, 465 



the tentacula, which leads to a cavity terminating in two 

 unequal recesses. The anterior is the smallest, and receives 

 the termination of a vessel three or four times longer than 

 the body, which takes its rise at the external base of 

 the cavity, apparently from the cellular substance, and, 

 after a variety of convolutions in the neighbourhood of 

 the mouth, opens into the recess. The second recess is the 

 largest, and the vessel connected with it is most compli- 

 cated. Its origin is in a mass which occupies a consider- 

 able portion of the abdominal cavity, and which consists of 

 a vessel forming a great number of complicated convolu- 

 tions, liberally supplied with bloodvessels. The duct 

 which proceeds from this mass, undergoes for a short space 

 a sudden thickening of its walls, after which it again con- 

 tracts, and, before it terminates in a perforated glandular 

 knob in the recess, it contains a pedunculated fleshy body, 

 with a sharp-pointed corneous extremity, probably capable 

 of being protruded into the recess and cavity. 



The parts which are considered as forming the female or- 

 gans, or those which are connected with the sexual cavity on 

 the right side of the anus, consist of an ovarium, divided into 

 two lobes, each of which may be perceived to be again mi- 

 nutely subdivided. The oviduct is tortuous, and passes 

 through a glandular body, which, in the other gasteropoda, 

 is regarded as the testicle. The pedunculated vesicle gives 

 out two ducts, one of which goes to the testicle, the other 

 to the uterus. It is difficult to form even a conjecture re- 

 garding the uses of all this complicated sexual apparatus. 

 The subject can only be elucidated by an attentive exami- 

 nation of the condition of the organs at different seasons of 

 the year, and by studying, at the same time, the habits of 

 the animals. 



The preceding description of the characters of the genus 

 is taken from the anatomical details of a species found 



VOL. II. G ff 



o 



