24 PEOF. M. M. HAETOG ON THE 



the granules, regarded as urinary by Leydig and Glaus, from their resistance to acids 

 and alkalies and their presence in the excrements. I have, however, failed to obtain 

 the murexide reaction in the stomach isolated on the slide. These concretions are 

 apparently removed by the casting off or degradation of the free ends of the cells con- 

 taining them, as they occur in the faeces surrounded by a clear space and membrane. The 

 muscular coat of the stomach is composed of an inner layer of longitudinal fibres, and an 

 outer of circular, all very fine, obscurely striated, and quite separate. The circular fibres 

 are reallv semicircular, extending from near the middle line of the one surface to that of 

 the other ; approximated towards their middle, and spreading out in fans on the upper and 

 lower surface, the fans of opposite sides being opposite one another. These circular fibres 

 are comparatively few and distant over the stomach, and in contraction sometimes make 

 it into a series of pouches. 



The intestine (PI. III. figs. 1, 3, i.) is a tube extending to the hinder end of the second 

 abdominal segment. It differs from the stomach in its more abundant transverse muscles 

 (of similar arrangement, howcAer), in its smaller lumen, and its less vacuolated shorter 

 columnar or cubical epithelial cells, which do not project in the same way at their ends, 

 except at the posterior boundary of the intestine, where they project inwards and forwards 

 into it to form a sort of prerectal valve (PL III. fig. 2, ^jr. v.). 



The rectum (PI. III. figs. 1, 2, r.) is a short tube with a very delicate chitinous cuticle 

 secreted by a tabular hypoderm, and with a strong close investment of circular muscular 

 fibres. It opens dorsally by two anal valves, leaving a dorsal longitudinal slit into the 

 squarish supra-aual cavity, partly overlain by the supra-anal plate. A row of fine teeth 

 or coarse setae extends along the dorsal side of each anal valve. 



The stomach is invested by connective tissue {"serosa" of Leydig) loosely connected 

 with the median line above, and with the side walls of the body so as to form mesenteries. 

 Two distinct anterior levators or protractor muscles, each a single slip, run from the upper 

 surface of the stomach, some way behind the junction of the anterior and middle thirds, 

 upwards and forwards, to be inserted into the parietal connective tissue of the body near 

 the middle line of the carapace, a little in front of the separation of the sexual ducts 

 from the generative gland. Two posterior levators* run from the junction of the 

 stomach and intestine to lie inserted in the anterior edge of the tei'gum of the third 

 thoracic segment, close to the middle line. 



The depressors (two pairs) are fine slips running obliquely outwards from the lower 

 serosa, diverging, as it were, from the four corners of a parallelogram, two forwards and 

 two backwards. From their position they are very difficult to see, only appearing in 

 horizontal sections of a certain thickness ; and the only ones I have clearly made out are 

 the anterior slips, originating from the sternal region at or behind the base of the post- 

 maxillary apodeme, and running upwards inwards and backwards. The two posterior, 

 I can see, are inserted further back on the lower serosa of the stomach, to which they 

 converge inwards and forwards from their origin. 



The intestine and rectum are fixed by two lateral pairs of mesenteries, deficient or 

 only represented by muscles posteriorly. They are moved by two sets of muscles, 

 median and lateral. The median are attached to the parietal connective tissue at the 



* These levators are best seen in living immature animals lying on their sides. 



