ECHIDJTID^. ' 375 



a. Muzzle comparatively short, straight 

 or slightly curved upwards. (Dorso- 



lumhar vertebras 16-3=19.) 1. Echidna, p. 377. 



a'. Basal leBgth about 90 to 120 



millim 1. E. aeukata, p. 377. 



6. Muzzle veiy long, curved down- 

 wards. (Dorso-lumbar vertebrae 



17^=21.) 2. Peoechidna, p. 382. 



6\ Basal length about 150 to 190 



millim 1. p. hruijnii, p. 383. 



B. Muzzle broad and flat, premaxiUse 

 widely expanded anteriorly. Teeth 

 represented functionally by horny 



plates • n. Omithorhynchidse, p. 386. 



c. Homy plates |x2=8 1. Oenithoehynchtts,p. 387. 



c\ Basal length about 80 to 110 



millim 1. O. amtinm, p. 388. 



. Family I. ECHIDNIDiE. 



Monotremes adapted for a terrestrial and fossorial ant-eating life. 

 Sexes not markedly different in size. Muzzle in the form of a slen- 

 der cylindrical beak, modified to protect the long, vermiform, and 

 extensile tongue. Fur thickly mixed with stout spines. Tail rudi- 

 mentary. Limbs short, subequal ; claws very broad and strong ; 

 toes not webbed. Palms and soles forming broad, soft, and fleshy 

 cushions, without distinct pads. 



Slcull with a large rounded brain-case and a long tapering ros- 

 trum, the premaxillae not expanded anteriorly. Squamosals large ; 

 zygomata slender, arising far forward on the brain-case. Palate 

 smooth, concave anteriorly ; without vacuities, but generally imper- 

 fect in the median line posteriorly. Pterygoids flattened horizon- 

 tally, and forming part of the floor and inner wall of the tympanic 

 cavity. Tympanic ring slender, incomplete, not anchylosed to the 

 other bones. Mandibles slender, styliform ; coronoid process and ' 

 angle rudimentary ; condyles small, longer than .broad. 



Teeth wholly absent. 



Range. Papuan and Australian subregions. 



References to Literature hearing on the Anatomy, Embryology, 

 Reproduction, Physiology, ^c. of the EchidnidsB. 



Home, Phil. Trans. 1802, p. 308 et seqq., pis. x.-xii. 



Meckel, Beytr. vergl. Anat. i. Heft ii. p. 64, pi. ix. (1809). 



BiiAiNTiLLE. (See under Omithorhynchidse.) 



D' Alton, Osteol. Zahnlosen Thiere, pis. iii. & iv. (skeleton) (1824). 



BuvBENOY, MSm. Soc. Strasb. i., Art. F, figs. A-0 (1830) (tongue). 



