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Show 62 MR. ST. GEORGE MIVART ON HEMICENTETES. [Jail. 17, formed entirely by the alisphenoid. The optic and sphenoidal opening is hidden by an alisphenoidal lamella. There is no long bony canal for the optic nerve to traverse, as in Erinaeeus, nor is there any suboptic foramen, nor any conspicuous orbital one. There is an alisphenoid canal, with its posterior aperture situated just in front of the foramen ovale, but it is much less conspicuous than in Centetes. There is no external alisphenoid canal. There is a distinct posterior palatine foramen on each side. The spheno-palatine foramen is hidden, unless it appears as a minute opening in the lower part of the large infraorbital canal. The anterior palatine foramen on each side is relatively rather large. The infraorbital foramen is exceedingly large, very much larger relatively than in Centetes, bounded above by a very delicate spiculum of bone. The lachrymal foramen opens immediately behind the summit of that delicate spiculum. There are two small foramina on the outer side of the very slender horizontal ramus of the mandible; the more anterior beneath the first premolar, the more posterior beneath the first molar. The dental formula is :- I. S C S P-M. g M. S=S=40. The upper incisors on each side are all separate from each other and from the canine ; and the first upper incisor is also separated by an interval from its fellow of tbe opposite side. The first two incisors on each side are of nearly the same size and shape. Each is conical, pointed, and much hooked, with a very large posterior lobe. Teetli of upper jaw, four times the size of nature. The third incisor is much shorter, gradually broadening downwards from the socket to the distal edge. The canine is shaped like the first two incisors, but rather larger, and with the posterior lobe relatively smaller. It i3 very much smaller, relatively as well as absolutely, than in Centetes. The first premolar, in shape and size, is very much like the canine, though separated from the latter by an interspace, which is about three times as long as that which divides the canine from the third incisor. The second premolar is shaped like the first premolar of Centetes. It is separated from the first premolar by an interval still greater than that which divides the first premolar from the canine. It has a posterior talon, but no internal cusp. Compared with the |