636 RODENTIA. INSECTIVORA. 



Sub-order 2. DUPLICIDENTATA. 



Incisors at birth f , the outer upper soon lost, the next pair 

 small and placed behind the large third pair (p. 628). Skull with 

 optic foramina confluent, without alisphenoid canal. Fibula 

 ankylosed to tibia and articulating with calcaneum. Testes 

 permanently external ; without vesiculae seminales. 



Fam. 20. Lagomyidae, Picas, p i or |, grinders rootless lopho- 

 dont, skull depressed, clavicles complete, ears short, no external tail. 

 Lagomys G. Cuv. (Ochotona Link.), pica, tailless hare, mountainous parts 

 of N. Asia, S. E. Eur. and Rocky Mountains, 16 sp. 



Fam. 21. Leporidae. Hares and rabbits, p |, skull compressed, 

 frontals with large wing-like postorbital processes, facial portion of maxillae 

 reticulated, clavicles imperfect, ears and hind limbs long, tail short; 

 cosmopolitan except Australasia and INIadagascar. Romerolagus Merr., 

 1 sp., Neotrop. Lepus L., hares and rabbits ; manus 5, pes 4 toes, about 

 20 sp. L. timidus (europaeus), hare ; L. cuniculus, rabbit, produces naked 

 young and lives in burrows. The common hare, hves on its " form," 

 produces active young, extends all over Europe, not known in Ireland. 

 L. variabilis, the mountain hare, often changes colour in winter, but does 

 not change in Ireland. 



Order 19. INSECTIVORA.* 



Terrestrial, rarely arboreal or natatorial mammals of small 

 size, with 'plantigrade or semiplantigrade, generally pentadactyle, 

 unguiculate feet ; with clavicles {except in Potamogale) ; with 

 more than two incisors in the mandible, and with enamelled, tuber- 

 culated rooted molars. 



The Insectivora are smaU animals covered with fur and some- 

 times on the dorsal and lateral surfaces with spines. The 

 limbs are usually pentadactyle, and the digits are armed with 

 claws. They are plantigrade or semi-plantigrade, and digit 

 No. 1 is not opposable in either foot. The extremity of the 

 muzzle projects beyond the end of the mandible. 



The dentition contains all kinds of teeth, but in many 

 cases the incisors, canines and premolars are not clearly dif- 

 ferentiated from one another ; it sometimes attains the full 



* Peters, Die Classification der Insectivoren, Monatsh. Akad. Wissensch. 

 Berlin, 1865. Mivart, Osteology of Insectivora, P.Z.S., 1871. Gill 

 Sjmopsis of Insectivorous Mammals, Bull. Oeol. and Geog. Survey, U.S.A. 

 1875. Dobson, Monograph of the Insectivora, London, 1882-90. Id. 

 Synopsis of the Soricidae, P.Z.S., 1890, p. 49, 1891, p. 349. Id., Insecti 

 vora in Blanford's Fauna of British India. Schlosser, op. cit., see Carni 

 vora. 



