520 MR. H. SAUNDERS ON LARIDE [June 6, 
small cavities which rather increase in size towards the surface of 
each gland. 
Anal Glands. 
There are constantly two anal glands, one on each side of the 
anus, in all A’luroids. The glandular structure may be a transverse 
band of follicles extending between the two anal giands, as in (at least 
some) Herpestes, Crocuta, and Proteles. The anal glands may be 
augmented to three pairs, asin Hyena brunnea', or even to five 
pairs, as in Crossarchus. These glands, together with the anus, may 
open into a deep anal pouch, asin the Hyenide, Crossarchus, Surt- 
cata, and Cryptoprocta; or the anus may open on the surface of the 
body, as in the Felide and almost all, if not all, the Viverrine. 
2. On some Laride from the Coasts of Peru and Chili, col- 
lected by Capt. Albert H. Markham, R.N., with Remarks 
on the Geographical Distribution of the Group in the 
Pacific. By Howarp Saunprrs, F.L.S., F.Z.S. 
[Received May 16, 1882.] 
(Plate XXXIV.) 
Capt. A. H. Markham, already well known for his circumpolar 
explorations, has availed himself of the opportunities afforded by his 
appointment to the command of H.M.S. ‘ Triumph,’ on the South- 
Pacific station, and has sent home from there an interesting col- 
lection of birds. The specimens belonging to the Procellariide have 
been placed in the hands of Mr. Osbert Salvin, who has made that 
family his special study; and the present paper is limited to the 
Laride, of which the collection contains examples referable to 15 
species. Amongst these is a specimen of that rarest of Gulls, and 
one of the rarest of all birds, XYema furcatum (the large forked-tailed 
congener of the cireumpolar Xema sabinii), a species of which only 
two examples were previously known, and the rediscovery of which, 
after forty years’ fruitless search, is due to the energy of Captain 
Markham. ‘ 
The following Laride were obtained between Payta, in 5° 11', and 
Coquimbo, in 30° S. lat. In addition to the original name of each 
genus and species, only those references are given which bear upon 
geographical distribution in the Neotropical Region. 
Na@nIA INCA (Lesson). 
Sterna inca, Lesson, Voy. ‘Coquille,’ ii. p. 731, Atlas, pl. 47 
(1826). 
Nenia inca, Boie, Isis, 1849, p. 189; Scl. & Salv. P. Z. 8. 1871, 
p- 567 ; Saunders, op. cit. 1876, p. 667. 
[No. 28(¢ adult), no. 29(¢ immature), Callao Bay, August 
1881. 
In the latter the general hue of the upper parts is of a smoke- 
1 Trans. Zool. Soe. vol. vii. p. 506. 
