942 



MK, 



F. E. BEDDARD ON THE ANATOMY [DeC, 14, 



transverse colon, this attachment commencing about an inch and 

 a quarter beyond the entry of the ileum into the colon. The 

 hepato-caval ligament is small, and at its extremity remote from 

 the liver just strays on to the kidney on one side and on to the 

 mesocolon on the other. 



The postcaval vein and its branches are exactly as I haye 

 described them in Fithecia pithecia. 



The intercostal system of arteries however differs. As in 

 P. pithecia, there are first of all three branches which are pre- 

 sumably oesophageal and pulmonary in distribution. The first 

 two intercostals are unpaired at their origin, and the subsequent 

 series though paired are much closer together than in Fithecia 

 pithecia. Whether this is really a specific difference remains of 

 course to be proved. 



I naturally paid very particular attention to the larynx of this 

 species for purposes of comparison with the rather abnormal 

 larynx of Fithecia pithecia, and discovered some differences which 

 however may be due to the greater immaturity of my example of 

 Fithecia monachi(,s. In this specimen in fact the two posterior 

 molars of each side of each jaw were quite invisible, there being 

 thus only four grinding teeth present out of a total of six on 

 each side of each jaw. The canines were considerably smaller 

 than those of the Fithecia pithecia, in which all the molars were 

 present. 



In general tispect the larynx of this monkey was like that 

 of Fithecia pithecia, but considerably smaller. This must be due 

 to youth, to some extent at any rate ; for the interspace between 

 the rami of the lower jaw was less in this Fithecia than in the 

 other. The diameter of this interspace measured at the beginning 

 of the ascending part of the mandible was 34 mm. in P. pithecia, 

 and 28 mm. in P. monachus. The mandible is, however, alto- 

 gether much smaller in the P. monachu,s. But while the two 

 individuals difl:er in actual size and in the size of the parts 

 adjacent to the larynx, thei'e is nothing like such an enormous 

 difference as that which exists between the larynges of the two 

 species of Fithecia, for the thja^oid cartilage in P. monachus 

 measures only 9 mm. in length by 12 mm. in breadth. It is 

 therefore about half the size of that of P. jnthecia. The propor- 

 tions of length and breadth are also, it will be observed, rather 

 different. The thyixnd is broader in the younger P. monachus. 

 This may be a specific difference. I regard as a sign of imma- 

 turity the form of the thyroid cartilage. In the adult Pithecia 

 pithecia it will be remembered that the ventral surface of the 

 thyroid is smooth and rounded. In the present species there is 

 anteriorly but not posteriorly a distinct though low median ridge, 

 thus preserving the more usual form of the thyroid cartilage in 

 Mammals. This ridge easily escapes the eye owing to the fact 

 that it is but little pronoiniced. It is nevertheless present. It 

 is quite easy to suppose that the subsequent growth of the thyroid 



