42 PROFESSOR OWEN ON INDIAN CETACBA. 



the exterior of the skull is much greater in Euphysetes breviceps than in Euphysetes simus, 

 especially in vertical extent : in the upper view of the skull the porportion of the postnarial 

 cavity, especially in breadth, to the extent of the rostrum is less in Euphysetes breviceps 

 than in Euphysetes simus. To these differences must be added the difference in the number 

 and shape of the teeth. In Euphysetes breviceps there are fourteen or fifteen teeth, or 

 sockets for as many, in each mandibular ramus : the entire tooth, figured by De Blain- 

 ville (copied in PI. XIV. fig 2. -b), is 10 lines in length, and has a proportionally larger 

 and more curved crown than in Euphysetes simus. De Blamville writes, " II me parait 

 a pcu pres certain qu'il n'y avait pas de dents a la machoire superieure" (I. c. p. 337) ; and 

 these are equally absent m Euphysetes grayi : the fu-st of the maxillary series remains 

 exposed, as a functional tooth, iu the quite adult skull of the smaller Indian species, 

 Euphysetes simus. From Euphysetes grayi the present species differs not only in this 

 dental character and its smaller size, but in its proportionally shorter muzzle, and in the 

 minor number and wider disposition of the mandibular teeth. Thirteen teeth are found 

 in each ramus of the lower jaw of the specimen of Euphysetes grayi in the Sydney 

 Museum : they are divided by interspaces of less than then- own basal diameter, and 

 have relatively longer crowns than those of E. simus. There are twelve teeth in the 

 right, and nine teeth ui the left ramus of the mandible of Euphysetes breviers, De 

 Blainv. : they are as wide apart as in Euphysetes simus, but have crowns more slender 

 and recurved. 



In the figures of the mandible given by De Blainville (loc. cit. pi. 10), and by 

 Macleay (loc. cit. pi. 2. fig. 5), the breadth between the outer parts of the condyles 

 equals the length of the mandible in a straight line, that is, fi-om the middle of the 

 cliord ch-awn between the condyles to the end of the symphysis. In Euphysetes simus the 

 breadth exceeds the length so taken. 



Among other differences between the present member of the Physeteridce and the 

 Lelphinidm (see Phoccena brevirostris, PI. IX. fig. 1) is the non-production of the upper 

 or hinder expansion (naso-frontal plate) of the maxillary (PI. XII. fig. I,2i» 21") over 

 tlie orbital process of the frontal( ii.u'); which, therefore, in Euj^hysetes simus as in 

 Euphysetes breviceps, stands out free (PI. XII. fig. 1, ii' ) from the upper and lateral 

 parts of the cranium behind the maxillary ( 21' 21"). 



Bones of the Trunk and Fins. (PI. XI. fig. 2.) 



Havuig been favoured with photographs of these bones in Euphysetes grayi by the 

 present able Curator (Mr. KreflFts) of the Australian Museum, I have thought it might 

 l)e useful to add the following notes : — 



Euphysetes (PI. XI. fig. 2) has fifty vertebra;, viz. seven cervical, fourteen dorsal, 

 twenty-nine lumbari-sacro-caudal : in the latter series the hsemapophysial arch first 

 ai)pears between the sixth and seventh (or between the twenty-seventh and twenty- 

 eighth vertebrse counting from the skull) : the hsmapophyses cease to be developed at 



