62 DR. LEIDY ON THE HISTORY AND ANATOMY OF 



the unattached extremity, but have no hair-like appendages as is stated to be the case 

 in the Nepadse generally. 



INTERNAL ANATOMY. 

 The description is taken from dissections of B. haldemanum. 



DIGESTIVE APPARATUS. 



The oral organs have been sufficiently dM^elt upon in the general description of the 

 animal. The oesophagus, narrow and delicate, extends into the metathorax where it 

 opens into the stomach. Its parietes are thin, but present three distinct tunics 

 beneath the microscope, an external homogeneous layer, an internal epithelial tunic, 

 and an intermediate layer of very fine muscular fibres. 



The stomach is large and irregular in form, and is much sacculated from numerous 

 contractions. In structure it is thin and has three distinct tunics : the external like 

 that of the oesophagus, structureless and homogeneous ; internally to this, a second 

 composed of transverse and longitudinal muscular fibres, of which the former are 

 more numerous and internal, and exist especially at the contracted parts of the organ 

 where they are accumulated into widened bands, and it is from tbisarrangement that 

 the sacculated appearance is produced ; the third or lining membrane is composed of 

 a net work of delicate fibres, with circular meshes, within which are situated round 

 glandular bodies, presenting under the microscope a structure of neucleated organic 

 cells. Passing from one glandular body to another, irregularly, are masses of adipose 

 matter, which with the glands project into the cavity of the stomach, and the whole 

 being covered by a delicate epithelium, it gives the inner surface of the stomach a 

 somewhat villous appearance. Opposite to the external contractions, valvulse or 

 short duplications project into the stomach. The stomach at its posterior part passes 

 insensibly into the duodenal portion of the intestinal canal. This latter is cylindrical, 

 convoluted several times upon itself, becomes rather dilated before joining the ileum, 

 and presents the same structures as the stomach. 



At the junction of the duodenum and ileum the hepatic tubes empty. 



The ileum is almost as long as the duodenum, pretty uniform in diameter, 

 convoluted several times upon itself, and presents a wrinkled appearance which 

 disappears by dilatation. "With the exception of the lining membrane, it is constructed 

 like the duodenum. 



The colon, a dilated portion of the intestinal canal, commences where the ileum 

 terminates. It is short, and is divided by a contraction into two portions, the posterior 

 of which may be considered as the rectum. Projecting forwards, from the anterior 

 part of the colon, beneath the abdominal viscera, there exists a large, capacious 

 coecum, longer than the colon itself, and longer in the female than in the male, which 

 the insect may use as a kind of natatory vesicle, for I have frequently seen 



