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Show 1881.] MR. F. E. BEDDARD ON HAPALEMUR GRISEUS. 397 to be "characteristic of all the species of the genus Lemur which have been examined, as well as Microcebus." It does not, however, exist in all the species of the genus Lemur : I have a sketch made by the late Mr. Forbes of the liver of Lemur mayottensis in which the extremely elongated gall-bladder has the normal characters, the fundus being turned away from the attached surface of the liver. I have (for m y own satisfaction) examined the liver of this animal, and can entirely confirm the accuracy of Mr. Forbes's observation. The spleen is very similar in shape to that of the Aye-Aye ; it is trihedral in form, the two portions of which it is composed being inclined at right angles ; they are subequal in size, the larger measuring 1\ inch in length. Bespiratory System.-The thyroid cartilage of the larynx is keeled on its anterior surface; at about the middle this keel is interrupted, and at this spot is a circular perforation which communicates with the interior of the larynx. In the Potto and other Lemurs the thyroid cartilage is similarly keeled, but there is no perforation. The lungs consist of three lobes on the left side and two on the right side ; of these the lower larger lobe is partially subdivided into two ; there is a small unpaired median lobe. The aorta, as in many other Lemurs, gives off a right innominate artery, from which both carotids and the right subclavian take their origin, while the left subclavian arises separately from the aortic trunk. The chief arteries of the limbs form retia mirabilia. The kidneys present no differences from those of other Lemurs ; the right is situated rather nearer to the diaphragm than the left; each kidney has a single papilla. The supra-renal bodies are long and oval, and situated in front of and to the inside of the kidneys. Generative Organs.-The generative organs closely resemble those of Lemur. There are two large vesiculae seminales, which lie close together behind the bladder ; the upper extremity of each is bent inwards and downwards, and its cavity is partially separated off by a strong fold; the internal surface of the vesicul'se seminales has a reticulated appearance, the lining membrane being raised into numerous folds which anastomose with each other ; below the vesiculae seminales are the prostates, which are compact glands sessile upon the wall of the urethra, divided into three pairs of more or less separate glands by deep furrows upon the outer surface. There are two large oval Cowper's glands situated further down, and opening into the urogenital canal about f inch below the aperture of the prostates : these glands are greenish in colour like the rectum, to which they are closely attached by membrane; each measures rather more than | an inch in length. On slittino* open the urogenital canal, an oval eminence is to be seen on the ventral surface ; the posterior extremity of this coliiculus seminalis is continued for some way down as a delicate fold, differing PROC. ZOOL. Soc-1884, No. XXVII. 27 |