87 



numerous large conical cells, the apex of each cell 

 pointing to the centre of the mass. Each cell has a well- 

 defined nucleus near its outer side. In the centre of each 

 gland mass is a small cavity into which the secretion from 

 the individual cells is poured. This small central cavity 

 is connected with the lumen of the oesophagus by means 

 of a long narrow duct which passes between the cells of 

 the epidermis. The duct and its walls is probably formed 

 of a single cell, in which case the gland duct is intra- 

 cellular. These glands are scattered through the 

 connective tissue of the oesophageal wall. They take the 

 stain distinctly, and have a diameter of 25 n to 35 // in 

 the small crab mentioned above. From the above 

 description it would appear that the oesophageal glands 

 are merely modified cutaneous glands. 



At the extreme ventral end of the oesophageal wall 

 at each side there is an additional mass of such glands 

 which are very closely packed together (v.oe.g.). As 

 mentioned above, these glands are continuous with those 

 of the mandible. 



The large and spacious region of the fore-gut which 

 follows the oesophagus is generally termed the 

 " stomach,"* and is divided into a large anterior portion 

 — the cardiac chamber (card.) and a smaller posterior 

 portion — the 'pyloric chamber (pyl.). 



The Cardiac fore-gut (PI. V, fig. 34, PI. VI, fig. 40, 



curd.) is a large simple sac roughly spherical in shape. 



The cuticle lining this part of the alimentary canal 



* The term "stomach" is an unsatisfactory one, as this part of 

 the fore-gut is neither embryologically nor physiologically what is 

 generally recognised as a stomach. Also the terms "cardiac" and 

 " pylroic " have no meaning when applied to the Malacostraca, seeing 

 that the cardiac region — as pointed out by Huxley — is the farthest 

 from the heart. It would be inconvenient, however, to reject the 

 terms " cardiac " and " pyloric," as such a change would also involve 

 an alteration in the names of numerous ossicles and muscles connected 

 with the fore-gut. The terms " cardiac fore-gut " and " pyloric fore- 

 gut " will be used in the present Memoir. 



