30 PEOFESSOE OWEN ON INDIAN CETACEA. 



The optic foramen communicates or is blended with a larger vacuity or fissure 

 between the orbitosphenoid, frontal and pterygoid, which might be termed the ^heno- 

 frontal fissui-e. The foramen rotunduni, in like manner, is blended with a larger vacuity 

 between the ali- and orbito-sphenoids, answering to the "fissm-a lacera anterior" of 

 anthropotomy, and which may be called the " intersphenal fissure "^ 



The removal of the loosely attached petrotympanic exposes the wide otocranial 

 \'acuity (PI. IX. fig. 3, or) in the basal walls of the cranium, which is a characteristic 

 featiu-e of the Delphinoid as compared with the Physeteroid skuU (PI. XIII. fig. 2), 

 where the otocranial is walled oiF from the cranial ca^dty. The oto.crane, in both, is 

 bounded by the paroccipital, basisphenoid, alisphenoid, and squamo-mastoid : in the 

 present species of Phoccena it presents a subquadi'ate form, 1" 4'" in diameter, with the 

 angles roimded off", notched anteriorly by the third division of the fifth, whereby the 

 "foramen ovale" blends with this great vacuity. 



The entocarotid foramen pierces the outer and fore part of the base of the otocranial 

 plate of the basisphenoid, close to, perhaps at, the line of confluence of the alisphenoid. 

 There are neither olfactory nor lacrymal foramina. The absence of the rhinal capsules 

 simplifies the condition of the prefrontals, and facilitates the comprehension of both the 

 special and general homologies of these interesting bones. A pan- of minute foramina 

 lead fi-om the cranial cavity to the narial ones piercing the prefontals ; but they do 

 not give passage to olfactory nerves in the Delphinidce. 



The departure from symmetry in the present Delphinoid skull is slight: it is seen 

 in the gi-eater backward extension of the nasal plate of the right premaxillary (fig. 

 2, 22" ), in the larger size of the prenarial plate of the right maxillary, and in a feeble 

 inclination of the upper margin of the septum narium to the left. 



FamUy PHYSETERID^ (Cachalots or Sperm-Whales). 



Genus Euphysetes, Macleay. 



Physeter (Euphysetes) simus, Owen. 



The Snub-nosed Cachalot. (Plates X.-XIV.) 



The Cetacean which I have next to describe is represented by drawings of the adult 

 male (side view, PI. XL to scale) and female (side view, PI. X. fig. 1 : upper view, fig. 2 ; 

 to scale). It is noted as " a kind of Porpoise " in Mr. EUiot's MS., and is known to 

 the Telugu fishermen of the coast by the name of " Wonga." The male, measuring 6 

 feet 8 inches in length, was taken at Waltair, February 28, 1853. The female was taken 

 on the 1st of March, 1853, at the same part of the coast ; she measured 6 feet in length. 



' It 18 noticed as " le trou spheno-orbitaire," by Cuvier, ' Oss. Poss." torn. cit. p. 294. 



