A Cephalophorous Mollnsk. 61 



The outlines of the following organs may be distinguished 

 through the somewhat transparent walls. 



The liver or digestive gland extends as a dark green mass, 

 from the apex of the spire, of which it forms the larger 

 part, to a point two revolutions lower down. It bears on 

 its dorsal surface the lighter sexual gland, testis or ovary, 

 the sexes in this univalve being separate. 



On the external surface of the liver the stomach is often 

 to be seen as a curved body somewhat less than the sexual 

 gland in size. Extending anteriorly from the liver, and con- 

 fined more to the outer portion of the whorl, is the dark- 

 colored renal organ or kidney. The outline of this organ, 

 when viewed from above, is triangular, the apex being di- 

 rected towards the columella, while the base extends laterally. 

 Viewed from the side, the base of the triangle is seen to rest 

 upon the liver, posteriorly ; upon the pericardial chamber, 

 ventrally ; and upon the roof of the mantle chamber, ante- 

 riorly. The renal organ is divided into a smaller tubuliferous 

 portion, which lies against the pericardium, and a larger acin- 

 ous portion, which lies above and around the first. 1 The line 

 separating the two runs parallel with the upper edge of the 

 pericardium. The pericardial chamber is somewhat cres- 

 centic in outline, and is about the size of one of the tentacles. 



If the specimen being examined is a female, the roof of 

 the mantle chamber presents on its dorsal surface a long, 

 large elevation of light cream-color, extending from the 

 liver, and internal to the kidney, nearly to the free edge of 

 the collar. This elevation is the nidamental gland. Through 

 its activity the long egg-strings are manufactured. Lying 

 parallel to, but outside of and below the nidamental gland 

 (nearer to the siphon tube), the location of the gill is clearly 



1 The function of the tubuliferous portion is uncertain. It is prob- 

 ably not excretory. 



