402 THE OSTEOLOGY OF VULPES MACROTIS. 



In the middle line of the base of this skull of V. macrotis, proceeding from 

 before backwards, we are enabled to see the vomer, the presphenoid and the basi- 

 sphenoid, and the sutures among them are fairly well defined. Still more posteriorly 

 the basi-occipital creates the roof of the narrow, Taut deep passage between the 

 auditory bullce, and its lateral margins are raised that they may better articulate 

 with those remarkable osseous capsules upon either side. Upon examining the 

 aperature of the Eustachian canal, the foramen lacerum medium, the foramen ovale, 

 foramen rotundum, the alisphenoid canal, the postglenoid foramejz, the foramen 

 lacerum posterius, the condylar foramen, the stylomastoid foramen, and some few 

 other features in this region of the base of the skull, they are seen to agree with 

 what is already known as to the cranial osteology of this family of mammals. 



The glenoid fossae are narrow and elongated ; their long axes being perpen- 

 dicular to the longitudinal axis of the skull. Behind either one is a conspicuous 

 post-glenoid process, curving downward and forward, and serving to retain the 

 condyles of the mandible in their sockets during life. Either auditory bulla is 

 hemi-ellipsoidal in form, — -thin and hollow. The exposed convex surface is ex- 

 tremely smooth, though in some species of the Canidae it may be slightly roughened 

 by delicate venations, but these are absent in the genus Vulpes. Within the 

 cranial casket a well-defined sella turcica is seen, and upon either hand, the internal 

 surfaces of the orbito-sphenoid bones. Anteriorly, the posterior margin of the 

 mesethmoid is inserted, forming, as usual, the crista galli. The cribriform plate is 

 extensive, and presents two suboval moieties with the posterior surfaces facing 

 backward and very slightly, upward. Internally, this plate is perfectly smooth, 

 and the foraminal perforations exceedingly numerous. 



As is the case in Cam's latrans, and other Canidae, the dense inner surface of 

 the vault of the cranium is marked by convolutions, to receive the correspond- 

 ing convolutions of the brain-mass, while the tentorium cerebelli very extensively 

 ossifies. All the fossae of the br&m-c&se— cerebellar, cerebral, and olfactory — 

 are well marked off, and comparatively capacious. Other features of the interior of 

 the brain-case are present, but being well known require no special description 

 here. 



The spongy bones of V. macrotis were not studied in section, but they are 

 probably as complicated as in C. latrans, of which such a sectional preparation 

 was examined. 



That they are so in many of the domesticated dogs has been clearly shown by 

 the late Sir William Henry Flower. 5 



These turbinal masses of bone in the olfactory chamber of the skull in mam- 

 mals are worthy throughout the class of our very closest study. Morphologically 

 they are full of interest, and should never be set aside as was the habit of the late 

 Dr. Elliott Coues, who thought them too complicated to be worthy of description. 

 Such an unscientific opinion was fully controverted by the late keen anatomist, Dr. 

 Harrison Allen, who devoted an entire memoir to the comparative morphology 

 5 Osteology of the Mammalia, pp. 129, 130. 



