1881.] MR. F. E. BEDDARD ON HAPALEMXJR GRISEUS. 397 



to be "characteristic of all the species of the genus Lemur which 

 have been examined, as well as Microcehus." 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 aivay from the attached surface of the liver. I 

 have (for my 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. 



Respiratory 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 lunys 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 Lenmrs, 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 Jcidneys 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 tvro 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 vesiculie 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 ihe 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 g an inch in length. 



On slitting open the urogenital canal, an oval eminence is to be 

 seen on the ventral surface; the posterior extremity of this colliculus 

 seminalis is continued for some way down as a delicate fold, differing 



Proc. Zool. Soc— 1884, No. XXVII. 27 



