1879.] MR. p. L. SCLATER ON A NEW HUMMING-BIRD. 145 



interrupting the continuity of the bony palate. Each of the two 

 anterior upper molars with two pairs of enamel folds, those of each 

 pair meeting interiorly and forming a kind of fork. Enamel folds of 

 the anterior lower molar more irregular ; the second with three folds, 

 the two anterior forming a loop'. 



Dentition of Tkrinacodits alhicauda. 



Thrinacodus albicauda. (Plate X.) 



Fur along the back of uniform softness and length, the longest 

 hairs being about an inch long; lower parts covered with shorter, 

 but likewise soft and dense fur. Bright reddish-brown above, the 

 longest hairs being black towards the extremity ; roots of the hairs 

 grey. Lower parts white. Basal half of the tail like the back, 

 termmal half white, with a greyish tinge towards the extremity. 



millim. 



Length of head and body 150 



Length of tail : 255 



Length of sole of fore foot 20 



Distance between heel and extremity of middle toe . . 38 



Length of skull 40 



Distance between the incisor and first molar 8 



Length of first upper molar 4-5 



Width of first upper molar 4 



February 18, 1879. 



Prof. W. H. Flower, Ll.D., F.R.S., President, in the Chair. 



The Secretary exhibited, on behalf of the Rev. F. O. Morris, an 

 example of Bombyx quercus with the antennae malformed, being 

 much smaller than the ordinary size. 



Mr. Sclater laid before the Meeting an example of a Humming- 

 bird obtained at Guajango, in Northern Peru, by Messrs. Stolzmann 



* Only the two front molars above and below have been preserved; the 

 third, which was still in an undeveloped condition, is lost. But it is not likely 

 that in the adult dentition the breadth of the molars would be diminished. 



Proc. Zool. Soc— 1879, No. X. 



10 



