230 DR.r.L. SCLATER ON THE GESTATION OF RUMINANTS. [Junft 9, 



The habitat of this species is not known, but is probably Africa. 

 Its nearest ally is the F. libitina, with which it forms a section of 

 the genus characterized by a superciliary plate more or less subdi- 

 vided, and leading off to Echidna. In the writer's opinion, the genus 

 Vipera is to be separated from Echidna by its large prenasal plate, 

 and postnasal slightly developed above the nostril, which is always 

 lateral : in Echidna the prenasal is replaced by scales, and the post- 

 nasal is much developed above the nostril, which is usually vertical ; 

 in E. atropus the nostril is vertico-lateral. 



One specimen of this Vipera belongs to the Academy of Natural 

 Sciences of Philadelphia, and another is in the British Museum. 

 For an opportunity of examining and figuring the latter, my acknow- 

 ledgments are due to the distinguished officers of the institution, 

 Drs. Gray and Giinther. 



3. Record of the Period of Gestation of certain Rumi- 

 nants WHICH BREED IN THE SoCIETy's GaRDENS. By P. 



L. ScLATER, M.A., Ph.D., F.R.S., etc., Secretary to the 

 Society. 



The period of gestation of certain animals of the class of Rumi- 

 nants which habitually breed in the Society's Menagerie has been 

 ascertained with tolerable exactness. Of course the period is slightly 

 variable ; but the times given in the following list are, on the average, 

 very faithfully adhered to, 



Fam. Cervid^. 



Wapiti Deer (Cervus canadensis). . 



Persian Deer ( C. wallichii) 



Barasingha Deer (C. duvaucelii) . . 



Japanese Deer (C. sika) (. r, ^^„iv,„ 



o u r» /n ■ t * J- \ r^ months. 



Sambur Deer (C. aristoteits) .... 



Busa Deer (C. rusa) 



Hog Deer (C porcinus) 



Axis Deer (C. axis) 



Fam. Camelid^. 



Lama (Juchenia glama) | j ^ ^_^^^^^^^^ 



Alpaca {A. pacos) J 



Fam. Camelopardid^. 

 Gir&ffe (Camelopardalis ffirqp^a) .. 15 months. 



Fam. BoyiD^E. 



Punjab Wild Sheep (Omcye/oeeros) 1 ^ months 



Moufflon Sheep ( O. musimon) .... J 



Leucoryx Antelope (Oryx leucoryx) 8 months. 



Eland Antelope (Oreas canna) . . 9 months. 



Nylghai Antelope {Portax picta) . Between 8 and 9 months. 



