1872.] DR. J. ANDERSON ON A NEW INDIAN MONKEY. 529 



gizzard-sacs — upon which these lateral muscles contract simul- 

 taneously ; and their arrangement is such that all the force of their 

 contraction is converted iuto a compressing force at right angles to 

 their direction. This force, by tending forcibly to obliterate their 

 included cavity, comminutes the more yielding of their contents and 

 squeezes from between them the resulting chyme, which finds no 

 difficulty in entering the small orifice to the duodenum*. 



2. On a supposed new Monkey from the S underbuilds to the 

 East of Calcutta. By John Anderson, M.D. 



[Eeceived January 15, 1872.] 



The natives of the district indicated in the title of this paper 

 assert that two Monkeys occur in it, viz. the red-faced Inuus rhesus 

 and another Monkey, which they state has no red about the face or 

 on the hinder quarters. Acting on this information, I sent a col- 

 lector to procure for me specimens of the two forms ; and he returned 

 with a number of undoubted examples of I. rhesus, and with two 

 fresh skins which appear to me to be very different from any adult 

 of I. rhesus that I have examined. The specimens in question were 

 shot about 50 miles to the east of Calcutta ; but as they only reached 

 me as skins I can only give the measurements of these, and of the 

 bones of the limbs and the characters of the skull. The longest 

 skin measures from the snout to the root of the tail 22". The tail is 

 12| inches long; the front limb 16" 6'" and the hind limb 18" 9'" in 

 length ; the hand is 4" 6'" and the foot 6" 9" long. The bones of the 

 limbs measure as follows: — humerus 6" 3'", radius 5" 10"',ulna6" 9'", 

 femur 6" 10'", fibula 5|f", and the tibia G" 3". The fur is thick 

 and rather woolly, and of a coarser texture than in /. rhesus, and 

 presents no trace of ambulation beyond the dark brown tips to 

 the hair. As in that species, it is longest on the fore part of the 

 body, especially on the interscapular region and shoulders and over 

 the humerus. It is uniform brown above and on the front of the 

 thighs, and pale on the outside of the limbs, but slightly darker on 

 the back of the hands and feet. The under surface and inside of 

 the limbs are of a dirty yellowish white ; the tail is brown above, con- 



* Since writing the above I find that there is a peculiarity in the gizzard- 

 pads in the Swan and Goose, which causes a slight up and down movement of 

 the lateral muscular masses when in action. The lower end of one pad and the 

 upper end of the other are much more strongly developed and are thicker than the 

 rest : this causes them to present a surface of contact one with the other, 

 which is somewhat oblique with regard to the axis of the lateral muscles. Con- 

 sequently, when these muscles come into play, the oblique surfaces tending to 

 come into contact, the material to be crushed intervening, they, being opposed 

 inclined planes, slide slightly on one another, the one mass rising while the other 

 descends. During the diastole of the gizzard it resumes its former relations, 

 and a reverse sliding occurs. 



Proc. Zool. Soc— 1872, No. XXXIV. 



