with a revision of the LimnceidcB of Authors. 337 



Two branches extend from the upper ganglion to the vicinity 

 of the heart, where another minute pair of ganglia was detected. 



From each of these a single nerve, which afterward divides, 

 proceeds in a posterior direction. 



Alimentary system. The oesophagus leaves the buccal mass 

 with two sudden flexures; it then becomes slightly dilated and 

 proceeds, curving with the shell, to the first half of the apical 

 whorl. Here it turns sharply «>n itself, the reflected portion 

 passing underneath the other, and. passing the posterior end, 

 enters the anterior end of the stomach. The latter, is ovoid, 

 strongly muscular, and recalls in appearance the gizzard of a 

 fowl. It is divided, apparently, into three indistinct regions, 

 of which the two outer are really muscular fibre and the inner 

 region is the cavity of the stomach. 1 found it full of commi- 

 nuted vegetable matter, among which were many small grains 

 of sand. Whether these are merely accidental, or serve the pur- 

 pose of triturating the food, there are no means of determining. 



The intestine leaves the stomach at the posterior end, and 

 passes beneath it, forward, without any marked flexure, follow- 

 ing the curve of the spire and opening on the left side of the 

 neck, just within the mantle cavity and close to the opening 

 of the vagina. 



A gland of a yellowish color, emptied bya duct which passes 

 into the throat, was supposed to be a salivary gland. 



The liver is of a greenish brown line, and extends nearly to 

 the apex of the spire. It is of no definite shape, but fills the 

 cavities between the lobes of the ovary and those in the region 

 of the stomach ; and is bounded, anteriorly, by the wall of the 

 pulmonary chamber. It is well supplied with blood-vessels 

 which ramify in every direction. The buccal plate Is BOme- 

 what cordiform or rounded triangular. It is smooth and of a 

 vellowish horn-color, but the cutting edge is slightly thicker 

 than the rest. A blunted rounded point forms the centre of the 

 cutting edge, which is Bimple and without notches or stria?. 

 There are no accessory plates. 



