596 MESSRS. SCLATER AND SALVIN ON PERUVIAN BIRDS. [Nov. 25, 
sions of the bodies of the two; but the Cephalophus dorsalis, never- 
theless, has much the stronger build. The head and ear of the 
latter are relatively and absolutely the largest, whilst the length of 
the tail preponderates in C. maawellit. C.dorsalis, C. macwellit 
in. in. 
“ Length from snout to root of tail(taken laterally) 273 26 
Height at shoulder (with straightened limb) .. 16 16 
— at hip (with straightened limb) ...... 17 17 
Dae MeHESt sors. 2: ae cae eee ee ees Se, | a a 
Length of tail to tips of hairs.............. 4 os 
of tail to the end of the vertebre .... 3 43 
Head: length, muzzle to occiput .......... 7 63 
Har, in preatest lengths... sas ss cece o> hs 3 2? 
“In the Bay Antelope the nasal and zygomaxillary regions are 
half an inch broader than in the other species, and they are like- 
wise more prominent and arched both across and lengthwise. 
“‘ The inside of the ear of C. marwellii is covered with long hairs ; 
in C. dorsalis the ears are bare, or have but a trace of short hairs 
near the margin. 
** Both species possess interdigital pits on all the feet, and both 
have shallow, rudimental suborbital glands; but the Bay Antelope 
differs markedly from the other in its possessing two deep inguinal 
sacs: there is neither an external nor internal trace of these in C. 
maxwellit. 
«As regards the internal organs, these are formed on the same 
ruminant model, there being four cavities in the stomach and a 
capacious cecum. There is a trenchant difference, however, in the 
comparative lengths of the intestinal tract, the stronger animal 
having the shorter gut. Thus in 
C. dorsalis. C. maxwellit. 
ft.- in: fs ts 
“The small intestine measures .......-.. 22 0 25 3 
The great intestine, minus czecum...... Coy, 10 3 
Mievcse Cun’. ete ee ate ori sie 5s 0 8 
“From the animals being both adult, of the same sex, and, 
broadly speaking, similar in size, it may reasonably be inferred that 
this striking variation arises from specific difference. Our want of 
knowledge of the precise food and habits of each in their native 
haunts debars a physiological reason being guessed at.”’ 
10. On Peruvian Birds collected by Mr. Whitely. By P. L. 
Scrater, M.A., Ph.D., F.R.S., and Osspertr Satvin, 
M.A., F.L.S.—Part V.* 
Since our last communication to the Society upon this subject 
two small collections have been received from Mr. Whitely. The 
* For Part IV. see P. Z. 8. 1869, p. 151. 
