149 



been killed, and then more or less devoured by the nocturnal murine omnivorous Rodent, 

 thus demonstrated to have acted in this carnivorous fashion by virtue of the pair of scal- 

 priform incisors " arranged collaterally in the axis," &c. But my objector's odontological 

 knowledge seems not to have included the fact, that there are several genera and species 

 of Cuviee's " Carnassiers " in which incisors having the size, form, and office of laniaries* 

 are not " held well apart through the interposition of a line of ' other ' incisors"f . 



The European Otter (Lutra) shows, indeed, this divaricate arrangement, but an African 

 Otter (Potamogale, Cut, fig. 1) does not ; a co-adapted pair of 

 laniaries (i 1) at the fore part of the upper jaw were opposed to a 

 slightly separated pair in the under jaw (i 2). 



In the Insectivora, as in the Marsupialia, there are two types of 

 the teeth which are developed and shaped " to pierce, retain, and 

 kill," in other words, two local conditions of " laniaries." In some, 

 Gymnura§, Centetes ||, e. g., the laniaries answer to the 'canines' of 

 Camivora, and are separated by interposed 'incisors' in both 

 upper and lower jaws, as they are in Sarcophilus and Thylacinus; 

 in other Insectivora the laniaries are approximated, and are formed 

 by 'incisors'; as, e.g. in Solenodon*^, Erinaceus**, Scalops, TJro- 

 triclius, and other Soricidce generally, in which a juxtaposed pair Laniary incisors, front 

 at the fore part of the mandibleff oppose a corresponding pair Tie . w ' Potamogale velox: 



I 1 t W X C G 11 1 1 1 . S 1 / ' _ - 



at the fore part of the upper jaw. These incisors usurp the 



functions of the canines in Gymnura, Talpa, Sec. The transference of the laniary form 

 and function from the canines to the incisors, the development of these latter into the 

 dental instruments " modified to pierce, retain, and kill," is the rule, or is found in the 

 majority of Insectivora. In the Japanese Mole-shrew (Urotrichus talpoides)$$ "the 

 incisor is long, conical, and pointed ;" it is grooved on the inner side : " the lower canine 

 is small, its office being transferred to the incisor"^. This large laniary tooth may be 



* " Technical canines vary as much in shape, proportion, and function as do technical 'incisors; ' are some- 

 times, indeed, implanted by two roots instead of one." See ' Odontography,' pi. 110. fig. 3 (Mole), 

 t X. p. 352 ; XI. p. 435. 



i For the subject of tins Cut I am indebted to the author of the instructive Memoir on Potamogale, Zool. 

 Trans, vol. vi. p. 1, Professor Allmax, F.E.S., of the University of Edinburgh, where the unique skeleton of 

 the Potamogale is preserved. 



§ Owex's ' Odontography,' pi. 111. fig. 4, a, b. 



|| lb. pi. 110. fig. 6. 



% ' Odontography,' pi. 111. fig. 1 (the front view (b) may be compared with that of Tlujlacoleo in XII. 

 p. 312, fig. 2). 



** lb. pi. 110. fig. 5. 



tt Sorex. — " In the lower jaw there is, as is known, one very elongated pointed incisor on each side." " The 

 canine is a small conical tooth, the smallest of the lower jaw." — Mivart, "On the Osteology of Insectivora." 

 Journal of Anatomy and Physiology, vol. ii. p. 11. 



Xt Catalogue of Bones in the British Museum, 8vo, p. 109. 



§§ Mivart, ut supra. 



6 



