646 



ON THE CIRCULATORY SYSTEM OF THE GRASS-SNAKE. 



O.A.R. 



Oc.A. 



Od. A. 



Od.A.P. 



Od.S.L. 



Od. S.R. 



Od. V.L. 



Od. V.L.P. 



Od.V.R. 

 Od. V.R.R. 



Oe.A. 

 Oe. V. 

 01. A. 



Olf. lo. 



Op. A. 



Opt. lo. 



Opt. Ner. 



O.P.V. 



Orb. 



O.S. 

 O.S.A. 



Ov.A. 



Ovar. L. 



Ovar. U. 



P. A. 



Fan. 



Far. 



Par. A. 



Par. A.A. 

 Par.P.A. 



Par. V. 



P.O. 

 P.C.V. 



Right Ovarian Artery. 

 Occipital Artery. 

 Oviducal Artery. 

 Posterior Oviducal Artery. 

 Lett Oviducal Sinus. 

 Right Oviducal Sinus. 

 Lett Oviducal Vein. 

 Left Posterior Oviducal 



Vein. 

 Right Oviducal Vein. 

 Right Posterior Oviducal 



Vein. 

 Esophageal Artery. 

 (Esophageal Vein. 

 Olfactory Artery. 

 Olfactorj' Lobe. 

 Ophthalmic Artery. 

 Optic Lobe. 

 Optic Nerve. 

 Oblique Palatine Vein. 

 Orbit. 



Orbital Sinus. 

 Anastomosis between the 



Orbital Sinus and the 



Maxillary Vein. 

 Smaller Ovarian Artery. 

 Left Ovary. 

 Right Ovarj-. 

 Parietal Artery. 

 Pancreas. 

 Parotid Gland. 

 Anastomosis between a 



branch of the Anterior 



and a branch of the 



Posterior Parotid Gland 



Arteries. 

 Anterior Parotid Gland 



Arterj^ 

 Posterior Parotid Gland 



and Superior Maxilhuy 



Artery. 

 Vein from Parotid Gland 



and also from neigh- 

 bouring muscles. 

 Primary Carotid Artery. 

 Post-Caval Vein. 



Pel. V. Vein probably corres- 

 ponding to tlie Pelvic 

 Vein of Lacertilia. 

 Fit. Fas. Pituitary Possa. 

 Pl.C.V. Palato-cerebral Vein. 

 Pl.P.V. Palato-pterygoid Vein. 

 Pul. A. Pulmonary Arter^'. 

 Pul.V. Pulmonary Vein. 

 P.V. Parietal Vein. 

 R.A. Right Auricle. 

 Ret. A. Retinal Arterv. 

 R.P.L. Left Renal Portal Vein. 

 R.P.R. Right Renal Portiil Vein. 

 R.R.A. Anterior Right Renal 



Artery. 

 R.R.M. Median Right Renal 



Artery. 

 R.R.P. Posterior Right Renal 



Artery. 

 Rt. A. Rectal Artery. 



R.V. Rostral Vein. 

 S.C.A. Short Ciliary Artery. 

 S.M.A. Superior Mesenteric 



Artery. 

 S.N. A. Anastomosis of the Sub- 

 nasal Sinuses. 

 S.N.V. Sub-nasal Vtin. 

 Sp. A. First Spinal Artery. 

 Sp. V. Spinal Vein. 

 Spin. Cor. Spinal Cord. 

 8pl. Spleen. 

 S.P.L. Lett Supra-renal Portal 



Vein. 

 S.P.R. Right Supra-renal Portal 



Vein. 

 S.R.L. Left Supra-renal Vein. 

 S.R.R. Right Snpra-renal Vein. 

 Sup. Lab. GI. Superior Labial Gland. 

 Sup. Fen. L. Left Supra-renal bodj'. 

 Sup. Fen. F. Right Supra-renal bodj'. 

 Th. A. Thyroid Artery. 

 Thi/. ai. Thyroid Gland. 

 Ton. Mus. Tongue Muscle. 

 Ton. SJi. Tongue Sheath. 

 V. Ventricle. 

 V.A. Vertebral Artery. 



PlATE LXX. 



Fig. 1. Diagram of the Heart and Blood-vessels in the anterior part of Tropidonotus 

 natrix. The two main arteries and veins on the ventral side of- the head 

 are indicated, but their precise distribution is dealt with on Plate LXXII. 

 Between the lines X.X. and Y,Y. a portion of the circulatory system is 

 omitted, as the relations of the Hepatic and Pulmonarj- Vessels and the 

 Dorsal Aorta are similar throughout the whole length of the liver. The 

 part omitted is about the sanje length as the distance from the thyroid 

 gland to the line X.X. For the purposes of diagram the liver is repre- 

 sented as pulled out to the right of the animal. The positions of the Liver 

 and Lungs are indicated bj' simple outline and those of the Gall-bladder, 

 Spleen, and Pancreas by shaded areas. 



Fig. 2. Diagranr of the posterior Blood-vessels in a female Tropidonottis natrix. 

 The positions of the kidnej^s and ovaries are indicated by simple outline 

 and those of the supra-renal bodies by shaded areas. For the purposes of 

 diagram the intestine is represented as pulled out to the right of the 

 animal, the fat-bodies as external to the oviducts, and the oviducts as 

 external to the ureters. Owing to the fact that the anterior end of the 

 . Fat-body is supplied from the right ovarian artery, while a little further 



