1882.] MR. W. A. FORBES ON THE GRE4T ANTEATER. 209 



opportunity of verifying, this median septum is developed along 

 the proximal (uterine) part of the vagina, instead of the distal 

 (external) as in Myrmecophaga^. 



As Pouchet, though describing the two apertures, does not men- 

 tion any median septum, it is possible that this vaginal septum may 

 disappear, as there seems to be good reason for supposing that it 

 does in Elephas indicus, in the gravid state. The penis in Myrmeco- 

 jihaga is so small that during coitus it is, I expect, entirely con- 

 tained in the urino-genital tube, and does not enter the vagina, as 

 is also the case in Elephas ; the disappearance of the vaginal sep- 

 tum can therefore hardly be due, in this species at least, to the non- 

 virgin condition of any particular female. 



4. As regards other points, I may mention that the external and 

 internal iliac arteries come oif separately, as in many other mammals % 

 there being no common iliac arteries. 



As in Manis tridentata as described by Rapp^, the chevron bones 

 in the tail contain a curious caudal rete mirabile, composed of both 

 venous and arterinl elements, which completely surrounds, as in a 

 sheath, a central artery of large size, which is the direct continuation 

 onwards of the abdominal aorta, and gives off here no branches at all 

 to the rete. The arterial elements of this rete are derived from 

 several small trunks on each side, which arise from the caudal artery 

 beyond the origin of the internal iliacs, and then break up into a 

 number of more or less parallel, rarely anastomosing, branches, 

 mixed up with which are similar venous trunks. A similar rete 

 occurs in Tamandua, and also, as I am informed by Prof. Flower, in 

 the Spider Monkeys of the genus Ateles. 



The paired eyelids are very small, and hardly exist as special 

 organs ; there are no eyelashes. The third eyelid, on the other hand, 

 is very large and well-developed. It contains a large cartilage of 

 concavo-convex shape ; on the internal surface of this eyehd, just 

 below the inferior border of the contained cartilage, opens the 

 minute aperture of the Harderian gland, which is very large, almost 

 completely surrounding the orbit, and concealing the much more 

 minute lachrymal glnnd. As described and figured by Pouchet, it 

 consists of three chief lobes. 



As already suggested by Chatin, I have little doubt that it is the 

 Harderian gland that has been described by Cuvier (Anat. Comp. 

 2me ed. iv. part 1, pp. 430, 431) and Owen (/. c. pi. xl. fig. 3 6) 

 in Cycloturus as a salivary gland opening into the mouth. 



Clavicles are frequently supposed to be absent in the Great Ant- 



' A similar condition of things to that here described in the genus Myrmcco- 

 phaga occurs sometimes, it may be observed, as a malfonnation, known as 

 " vagina duplex et uterus simplex," in the human female, the vagina being more 

 or less completelj' divided into two chambers bj' a median septum, and open- 

 ing externally by fu:o quite separate orifices. Cf. a paper by Dr. T. Matthews 

 Duncan, Jouru. Auat. Pliys. i. pp. 2ti9-274, and Dr. Morrison Watson's paper, 

 "The Homology of the Sexual Organs illustrated by Comparative Anatomy and 

 Pathology," I.e. xiv. pp. ()0-t)2. 



- Cf P. Z. 8. 1681, p. 188, 



" L. c. p. 92. 



