520 MR. H. SAUNDERS ON LARID^E [Juiie 6, 



small cavities whicli 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 Jiluroids. The glandular structure may be a transverse 

 band of follicles extending between the two anal glands, as in (at least 

 some) Herpestes, Crocuta, and Proteles. Tl)e anal glands may be 

 augmented to three pairs, as in Sycena brunneu \ or even to five 

 pairs, as in Crossarchus. These glands, together with the anus, may 

 open into a deep anal pouch, as in the Syanidce, Crossarchus, Suri- 

 cata, and Cryptoprocta ; or the anus may open on the surface of the 

 bodv, as in the Felidce and almost all, if not all, the Viverrina. 



2. On some Laridce from the Coasts of Peru and Chili, col- 

 lected by Capt. Albert H. Markliam; R.N., witli Remarks 

 on the Geographical Distribution of the Group in the 

 Pacific. By Howard Saunders, F.L.S., F.Z.S. 



[Eeceived May 16, 1882.] 

 (Plate XXXIV.) 



Capt. A. H. Markham, already well known for his circunipolar 

 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 ProcellariidcB 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 

 LarideB, 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, Xema furcatum (the large forked-tailed 

 congener of the circunipolar 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 Zan'rfce were obtained between Payta, in .5° 11', and 

 Coquirabo, 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. 



N^NiA iNCA (Lesson). 



Sterna inca. Lesson, Voy. ' Coquille,' ii. p. 731, Atlas, pi. 47 

 (1826). 



NcBtiia inca, Boie, Isis, 1849, p. 189 ; Scl. & Salv. P. Z. S. 1871, 

 p. 567 ; Saunders, op. cit. 1876, p. 667. 



[No. 28 ( cJ adult), no. 29 ( c? immature), Callao Bay, August 

 1881.] 



In the latter the general hue of the upper parts is of a smoke- 

 ' Trans. Zool. Soc. vol. vii. p. .Wfi. 



