190 J. E. S. MOOBE. 



structures described by Collier,^ Huxley,^ Haller,^ and others, 

 and the morphological conclusions which can be drawn from 

 the nature of the stomach are in harmony with those which I 

 have pointed out in reference to this Gastropod's ganglia and 

 nerves (see p. 187). 



On leaving the stomach the intestine bends twice in the 

 manner represented in fig. 42, and towards its rectal extremity 

 it is considerably enlarged (fig. 49, 1). This enlargement 

 contains the curious glandular fold represented in fig. 46, i. 

 The anus is carried on a slight projection of the rectum from 

 the mantle wall, and during life is slightly in advance of the 

 margin of the mantle (fig. 2, 7). 



The "Liver" occupies the lower portion of the upper 

 whorls of the shell (fig. 2, 6), and has the usual characters of 

 a digestive gland. The "bile-ducts" open by two orifices in 

 the floor of the stomach, behind the pyloric aperture. 



The Kidney occupies the region behind and to the left of 

 the heart (fig. 3, 6), and opens by a single minute pore, quite 

 at the posterior extremity of the mantle cavity. 



The Heart and Gills. — The heart is simple, lying rather 

 obliquely at the end of the mantle cavity. There is a large 

 pericardial chamber (fig. 3, 5). The ventricle tapers from 

 before backwards, and is surmounted by a large, rather thin- 

 walled auricle, which in turn receives the pulmonary vein. 

 There are well-formed valves between the auricle and the 

 ventricle (fig. 48, 1), and between the ventricle and the aortic 

 trunk (fig. 48, 4). From the aortic trunk the anterior and 

 posterior aortse diverge in the usual way (fig. 48, 7, 8). 



The gill in Typhobia (fig. 3, 7) is very long, extending 

 from the base to the margin of the mantle cavity. It is com- 

 posed of simple broad-based triangular leaves, the apices of 

 which are elongated. The osphradium lies at the base of a 

 groove ; it is long and simple, not fimbriated or gill-like, in 

 fact a mere ridge (fig. 3, 8). This ridge is innervated by a 



1 Collier, ' Edin. New Phil. Jouru.,' vol. vii, 1829, pp. 230, 231. 



2 Huxley, ' Phil. Trans.,' 1853, p. 10. 



^ Haller, ' Morph. Jahr.,' Bd. xix, 1893, pp. 582—584. 



