204 MERISTIC VARIATION. [part I. 



But whether the oblique tooth, or the tooth between it and 

 the right i 1 , should be rather considered supernumerary cannot 

 be declared with certainty. Probably this is one of the cases, of 

 which more will be said hereafter, in which both teeth replace the 

 normally single i\ C. S. M. 21, A. 



287. Anomalous extra teeth. A lower jaw in the Museum of the Odontological 

 Society "having two supernumerary teeth embedded in the bone beneath the coro- 

 noid process and sigmoid notch. Originally only a small nodule of enamel was 

 visible on the inner surface of the right ascending ramus, just external to the upper 

 extremity of the inferior dental canal. On cutting away the bone this nodule was 

 found to be a portion of a supernumerary tooth having a conical crown and a 

 single tapering root. Lying above it, another supernumerary tooth was discovered, 

 of which there had previously been no sign whatever. This was likewise exposed 

 by removing the superjacent bone, and found to be a larger tooth with a conical 

 crown and three long narrow roots. The teeth were lying parallel to each other, 

 with their crowns pointing upwards and backwards, so that they could hardly under 

 any circumstances have been erupted in the alveolar arch." Trans. Odont. Soc, 

 1887, xix. p. 266, fig. 



Specimen having fragment of a tooth imbedded in bone between left lower canine 

 and p 1 ; perhaps a fragment of a milk-tooth P.M., A, 506. 



[Two specimens in the stores of the P.M. shew great irregularities in the 

 arrangement of the teeth ; but in both cases so many teeth had been lost during 

 life that a satisfactory description of the abnormalities cannot now be given.] 



Hylobates (Gibbons). 



Normal specimens seen, 51. No abnormal case known to me. 



Old World Monkeys other than Anthropoid Apes. 



188. Of the genera Semnopithecus, Colobus, Nasalis, Cercopithecus, 

 Cercocebus, Macacus and Gynocephalus ; 419 normal specimens 

 examined. Only two had definite supernumerary teeth, but in one 

 other case it was possible that extra molars had been present. 



Supernumerary molars. 



189. Cynocephalus porcarius, having large extra molar behind 

 and in series in each upper jaw. The two teeth are of the same 

 pattern precisely. In lower jaw there is on each side a large 

 space behind m 3 , but there is no tooth in it. 0. M., 2011, b. 



190. Macacus rhesus, old male, having a fourth molar in place in 

 right lower jaw. The tooth does not stand up fully from the 

 bone. On the same side in the upper jaw there is also a fourth 

 molar, but was entirely enclosed in bone and was only found by 

 cutting away the side of the maxilla by way of exploration. B. M., 

 30, c. 



191. Macacus radiatus, having small and fairly definite depression behind mjj in 

 each jaw. These depressions seem to be perhaps the alveoli of teeth but it cannot 

 be positively stated that extra molars have been present. C.S.M., 145. 



192. Abnormal arrangement. Only one case of considerable irregularity of arrange- 

 ment seen, viz., Cercopithecus lalandii (C. S. M. 113), case in which lower canines 

 are recurved and pass behind the upper ones. See Cat. Mas. Coll. Surg. 



