78 SECOND Y AUK AN I) MISSION. 



A comparison of these measurements with those given for L. auritus will show how very 

 close they are to each other ; the principal distinction heing that in L. griseus the nasals are 

 broader behind, and the posterior portion of the palatine opening is much more open than in 

 L. auritus. There are also important external differences between the two species ; the hair 

 in L. griseus is longer and rather softer ; it is especially longer on the face, and has all the 

 basal portion in that region black, whilst in L. auritus the basal portion of the hairs on the 

 head is light-grey. The general colour of the two species, too, is quite different, L. auritus 

 being brown, whilst L. griseus is grey. 



Prom L. macrotis the present species is distinguished by colour, and the skull differs 

 in the same characters as it does from that of L. auritus ; the nasal bones being broader 

 behind and the posterior portion of the palatine opening more open. The bony orbits also are 

 rather smaller in L. griseus. 



The nasal bones of L. griseus approach in shape those of L. roylei, being nearly as broad 

 behind as in front, but they are longer. 



It appears possible that L. auritus, L. griseus, and L. macrotis are all races or sub- 

 species of one typical form just as L. roylei, L. nipalensis, and L. tibetanus appear to be. 

 All these forms are very closely connected. 



The other species of Lagomys known from Asia are L. roylei? from the North- West 

 Himalayas, L. hoclgsoni," from the same region, considered subsequently by its describer 

 identical with L. roylei, L. nipalensis, 1 from Nipal, and L. curzonice* from the Chumbi valley 

 north-east of Sikkim. By Mr. Waterhouse s L. nipalensis was considered a distinct species, 

 but Mr. Blyth 6 united it, as well as his own species L. hoclgsoni, to L. roylei. As noticed 

 under L. laclacensis Dr. Stoliczka, in 1864, 7 identified the common Lagomys of Ladak with 

 L. curzonia?, but the species occurring in Sikhim was found to agree better 8 with Mr. Hodg- 

 son's description than the Ladak form did, and I consequently suggested that the latter would 

 prove to be an undescribed species, whilst I was disposed to consider the true L. curzonia as 

 a variety of L. roylei. Dr. Giinther has, however, 9 recently examined the species represented 

 in the British Museum, and he considers L. curzonia a well marked and distinct species, and 

 from his description I am inclined to doubt if the Sikkim form is really L. curzonia. 



An additional species has been admirably described and figured from Moupin in Eastern 

 Tibet by A. Milne-Edwards 10 under the name of L. tibetanus : this, however, appears very 

 closely allied to L. roylei and L. nipalensis. 



The above are all from the Himalayan ranges and Tibet, but the genus is also well re- 

 presented in Northern Asia, where the three oldest known species occur. These were des- 

 cribed as long ago as 1778 by Pallas 11 as Lepus pusillus, L. alpinus, and L. ogotona; the first 

 from the Southern Ural, the second from the Altai, and the third from the neighbourhood of 

 Lake Baikal and the deserts of Mongolia. To these a fourth was added by Pallas 12 from 



1 Ogilby in Royle's illustrations of the Botany, &c, of the Himalayan Mountains, p. lxix, pi- 4. 



2 Blyth, J. A. S. B., 1841, x, p. 816, PI. at p. 844. 



3 Hodgson, J. A. S. B., 1841, x, p. 854, PI. at p. 816. 



4 Hodgson, J. A. S. B., 1857, xxvi., p. 207. 



5 Mam., ii, p. 24. 



6 Cat. Mam. Mus. As. Soc, p. 133. 



7 J. A. S. B., 1865, xxxiv, pt. 2, p. 108. 



8 J, A. S. B., 1872, xli, p. 35. 



9 Ann. Mag. Nat. Hist., Ser. 4, xvi, p. 230. 



10 Eech. Mammiferes, i, p. 314, PI. XLVIII and XLIX. 



11 Glires, pp. 28-70, Tab. I, II, III and IV. 



12 Zoog. Eos. As., i, p, 152. 



