344 MB. F, E. BEDDARD ON THE [Feb. 16, 



each other. They (the artery to the fat-body, the inferior mesen- 

 teric, and the fii'st intestinal) arise in the following order : — 

 (1) anterior spermatic; (2, 3, 4) three arteries to vas deferens; 

 (5) fat-body artery ; (6) first right renal ; (7) posterior sper- 

 matic ; (8) inferior mesenteric; (9) second right renal; (10) 

 artery to vas deferens; (11) first intestinal; (12) first left 

 renal (with branch to vas deferens) ; (1 3) thii'd i-ight renal ; 

 (14) second left renal ; (15) fourth right renal. 



The left kidney has in all 8 arteries and the right much 

 the same, though I cannot be so precise. 



Coluber melanoleucus. 



Anterior Vertebral Artery. — This artery is moi'e extensive in this 

 species than it is in many Snakes. It runs up to the neck to 

 within an inch of the head, where it becomes lost in the thickness 

 of the parietes. It gives off a number of intercostal branches, 

 which are exactly median in their entrance into the dorsal 

 parietes. The nine anterior arteries of this series appear to me 

 to be regulaily intercostal and each to correspond to a vertebra. 

 After this point the arrangement is not so regular. Between 

 this point and the origin of the vertebral artery there were only 

 8 intercostals and 1 very minute one. It may be remarked that 

 where the intercostals are regular in their arrangement they are 

 to a large extent smaller than those arteries set at irregular 

 intervals. 



Intercostal Artet-ies. — The right aorta before it joins the left 

 gives ofi" but a single intercostal, which perforates the body- wall 

 to the left of the dorsal median line. The intercostals which 

 arise after the junction of the two aortse are not so numerous 

 anteriorly as they become posteriorly ; and, furthermore, these 

 anterior arteries perforate the body-wall to the left of the middle 

 line. Only ten of these arteries arise from the aorta up to the 

 posterior end of the stomach, and they all of them enter the 

 parietes on the left side of the dorsal median line. From this 

 point onwards there is an irregularity and alternation in the 

 place of entrance of the intercostals. The 35 or so of them 

 which arise from the posterior section of the aorta are obviously 

 more crowded together than the anterior set. A few of them 

 are strictly paired. 



Gastric Arteries.- — The ai-teries supplying the stomach are 

 apparently 11 in number, of which the first six are insig- 

 nificant in size, and the ninth is the largest. They are all 

 concerned with the feeding of two longitudinal trunks which 

 run along the surface of the stomach, and have a markedly 

 undulatory course with the loops closely approximated to allow, 

 of course, of the distention of the stomach without injury to 

 themselves. These arteries, which arise from the aorta, are given 

 oif in alternating positions, according to whether they debouch 

 into the right or the left longitudinal trunks. The first of the 



