COMMON RINGED SNAKE. 69 



The pericardium has been cut away. The right auricle is large and 

 has its wall removed to show the right auriculo-ventricular aperture. The 

 left auricle is small and is crossed by the left jugular vein. The ventricle 

 touches the small and rudimentary left lung, and rests upon the large and 

 long right lung which lies behind the liver. Crossing the ventral surface of 

 the right lung is the vena cava inferior, accompanied by the pulmonary 

 artery which lies to its outer side. The liver is long and unilobar. A furrow 

 on its outer surface lodges the vena cava inferior. The gall-bladder is 

 large, and lies about a half inch from the posterior end of the liver. It is 

 bent sharply upon its duct, beneath which a piece of blue paper has been 

 passed. This duct and the bile duct unite inter se, and with the pancreatic 

 duct in the substance of the pancreas, a globular gland lying on the intes- 

 tine close behind the gall-bladder. The first portion of the intestine is 

 straight, but from the pancreas onwards it is disposed in short abrupt coils. 

 These are supported by a mesentery, but the peritoneal coat does not 

 follow every turn of their course as is usual, but passes from the end of one 

 coil to the end of the next succeeding. The coils are closely united by 

 connective tissue. 



The lobed fat body commences about the level of the pancreas. It is 

 fastened out on the animal's right side ; the branches of a vessel, the 

 remnant of the epigastric vein, may be seen here and there among its lobes. 

 The vessel in question joins the portal vein. About four inches from the 

 liver is the right ovary with a single row of ova, and between it and the 

 fat body is the vascular oviduct. The left ovary and oviduct have similar 

 relations on the left side, but are placed more posteriorly. The same 

 asymmetry is visible in the position of the two kindeys, organs consisting of 

 a number of leaf-like lobes placed one behind the other. Close to the 

 cloaca, the large intestine is seen lying between the two oviducts. It has 

 been opened and a black bristle passed, through it into the cloaca. The 

 left oviduct has a white bristle similarly inserted into it. The skin and 

 muscles behind the cloaca have been removed to show the two sacs, homo- 

 logues of the two eversible sacs or intromittent organs of the male. 



The following points of anatomy may be noted, not visible in the specimen. 

 The subcutaneous connective tissue is very scanty in amount and absent altogether 

 on the abdominal surface. 



Nervous system. The olfactory lobes of the brain are swollen terminally and 

 are long ; the prosencephala broad ; the cerebellum somewhat tongue-shaped and 

 projecting over the fourth ventricle. The pituitary body is broad. The parts 

 of the brain lie nearly all in one plane. There is no spinal accessory nerve. 



Special sense organs. There is no tympanic cavity. Among Lizards, the 

 Geckoes (Ascalabota) Amphisbaenae and some others resemble the Ophidia in the 

 fusion of the eye-lids. There is thus formed a lacrymal sinus. 



