44 



MR. R. I. POCOCK ON THE EXTERNAL 



difiers from that of all the Lemur oid Primates examined by me. 

 Above the orifice there is a transverse glandular depression 

 overlapped by a thick flap of epithelium. A somewhat similar 

 crescentic flap half encircles the bacular pad laterally and below. 

 The baculum (text-fig. 14, A, B) itself is a little longer than that 

 of an adult example of Lemur albifrons more than twice the size 

 of Chirogaleus major. Seen from the side the baculum shows a 

 slight sinuous curvature, the distal half being depressed. Seen 

 from above or below, the main part of the shaft is straight and 

 subcylindrical, but its apical fourth is divided into two curved 

 branches, a right and left, which diverge at first, then converge 

 so as almost to meet apically in the middle line, circumscribing 

 an ovate space. The urethra, which runs along the underside of 

 the main portion of the baculum, passes through this space at 

 the point of bifurcation of the baculum. Hence it comes about 

 that the orifice of the urethra lies above the pad which covers the 

 juxtaposed tips of the two branches. 



In being distally biramous the baculum of Chirogaleus resembles 

 that of the lndrisine Lemurs, a point of great interest. It is 

 most like that of Lichanotus, but has the base less expanded and 

 the branches curved and convergent apically instead of widely 

 divaricated. According to Beddard Hapalemur also has a 

 bifid baculum. I do not know the course of the urethra with 

 regard to the baculum in the Indrisidse, nor is Beddard quite 

 clear on this point in his description of the penis of Hapalemur, 

 but since he states that the urethra opens at the posterior end 

 of a groove marking on the glans penis the forking of the 

 baculum, it may be inferred that the orifice of the urethra is 

 beneath the tip of the baculum as in typical Lemurs and not 

 above it as in Chirogaleus. 



On one of the plates of his unfinished work Milne-Edwards 

 illustrates the male genitalia of a Lemur which, although un- 

 named in the legend, is clearly shown to be L. catta by the naked 

 scrotum. Four bacula are figured on the same plate. They 

 may have been taken from specimens representing four distinct 

 species or from four examples of L. catta. If the latter, the 

 figures attest a certain amount of individual variation in this 

 bone, particularly in width at the base and expansion and 

 curvature at the tip. There the matter must rest. 



In the species I have examined, namely L. catta, macaco, 

 albifrons, and coronata, there is very little variation in the penis 

 and baculum. The penis (text-fig. 13, M-P) is subcylindrical 

 and armed in the middle of its length with many reversed spines 

 which are mostly of small size ; two or more pairs, however, on 

 each side are much larger than the others, but these large spikes 

 are not always either symmetrically placed or numerically iden- 

 tical on the two sides. The orifice of the urethra is terminal 

 and opens just beneath the tip of the baculum. The baculum is 

 a comparatively short and slender rod with a larger proximal and 



