28 



flexor longus poUicis. This compound muscle, occupying the whole 

 posterior surface of the bones of the leg, so pushes round the tibialis 

 posticus, that it takes the chief part of its origin from the inner side 

 of the tibia, which in Mammalia generally is free from muscular 

 attachment. In the Paradoxurus I found that the flexor longus 

 digitorum has, in addition to its usual attachments, a point of origin 

 inthe head of the fibula ; but then the bones are separate, and the 

 flexor longus pollicis is a distinct muscle, having also origin in both 

 bones, and each tendon passes the ankle in its usual place*. 



March 13, 1849. 

 W. Yarrell, Esq., Vice-President, in the Chair. 



The Secretary reported that a living specimen of Serpestesfasciafus, 

 Desm., and Coeloffemjs jiaca, Linn., had just been added to the So- 

 ciety's collection. The former animal was exhibited to the Meeting. 



The Secretary directed attention to a small series of skins of Mam- 

 malia and Birds collected in Ceylon and Sennaar by Aubrey Paul, 

 Esq., the species of which were briefly noticed by Mr. Gray and 

 Mr. Goidd. 



The following papers were read : — 



1. Notice of a peculiarity of structure Observed in the 

 Aorta of the Wild Swan. By John Davy, M.D., F.R.S. 

 L. & E., Inspector-General of Army Hospitals, etc. 

 (Communicated by Mr. Gulliver.) 



When engaged in examining anatomically this bird (a full-grown 

 female, killed in the neighbourhood of Chatham in February 1 839), 

 my attention was arrested by a peculiar appearance in the inferior 

 portion of its aorta, which I shall briefly describe with the hope of 

 leading to further inquiry. Before the ischiatic arteries are given ofl^, 

 the aorta is comparatively large and is enveloped externally in a dense 

 fibrous coat, possessing very little elasticity : below the origin of these 



* Since writing the above I have taken opportunities of looking at the same 

 muscles in a Fox and in a Monkey {Cercopithecus pygerythrus). The former animal 

 differed from the Paradoxurus, and resembled the Jerboa, in the great extent of the 

 flexor longus pollicis and the much-reduced size of the tibialis posticus, which here 

 also terminates in a long slender tendon, showing an interesting correspondence of 

 adaptive character in two animals, in which the motion of the hind-limbs is vi- 

 gorous, but of one kind only. In the Monkey the flexor longus pollicis is a much 

 larger muscle than the flexor longus digitorum, and has considerable attachment 

 to the tibia. 



Meckel and Cuvier allude to the union of the two long flexors in the Rabbit 

 before they pass the ankle, but neither author informs us at which point that takes 

 place. 



