FOSSIL GENUS BASILOSAURUS. 9 



which I had examined in Albany. I founded the distinction on the hollowness of the 

 teeth and the more elongated, gavial-Hke form of the beak. The following is the 

 description, slightly amended, which I then gave of these teeth. (PI. IV. figs. 1, 2, 4.) 

 " Teeth spear-shaped, the crowns compressed laterally, and in distinct, deep sockets, 

 with double fangs ; the bifurcation commencing a half inch below the enamel, which 

 extends from the point of the tooth one inch ; enamel smooth, except near the base, 

 where it is wrinkled vertically ; the serrse longitudinal, diminishing in size from the 

 apex of the tooth, which is seven-eighths of an inch from the first lateral point ; 

 length of the tooth 2i inches; breadth 2i inches; thickness of the body below the 

 enamel, a half inch ; the anterior root a cone, compressed laterally ; the other pris- 

 matic, thiclcer on the posterior side, which is fluted so as to present the appearance of 

 being partially divided into two fangs : where the fangs are united, the neck is con- 

 tracted, so that a horizontal section presents the yoke-shape of the Zeuglodon of Owen. 

 In one of the teeth the distance from the extremities of the fangs across is 2§ inches." 

 Besides the serrated molar teeth, which are figured in a portion of a lower maxilla, 

 and which are all similar, I have two kinds of perfect canine te '.th of a single fang 

 each, one of which was then, and both of which are now, figured. One is curved, 

 compressed and pointed, resembhng very much a figure given by Faujas de St. Fond* 

 of a tooth of the Asiatic crocodile or gavial ; though it has no appearance of a second- 

 ary tooth, and is contracted at the extremity of the fang, and inserted obliquely in 

 the socket. It is much compressed laterally and longitudinally, and is hollow, the 

 dentine thin, but the enamel developed. A depression on each lateral surface almost 

 gives it the appearance of being lobed, showing the tendency to the yoke form in the 

 section. It has also cutting edges on the anterior and posterior compressed sides of 

 the enamelled crown, and in appearance resembles very much the teeth of Megalo- 

 saurus, though the edges are not serrated, (PI. IV., fig. 3.) The other canine tooth, 

 (PI. II., fig. 1,) is more straight until within the distance of the enamel from the point, 

 which is slightly curved. The body below the enamel bulges out, and is not com- 

 pressed laterally like the former specimen. Casts of both these teeth, and of the 

 molars, were forwarded to Prof Owen by my friend Dr. S. G. Morton, who has 

 kindly favoured me with a letter from that distinguished naturalist, containing his 

 impressions on the subject. 



"RoY.vL College of Surgeons, Nov. 11, 1845. 

 "I have been much gratified by finding, on my return from a tour in Italy, addi- 

 tional examples of your friendly remembrance in the interesting cast of the tooth on 

 which Dr. Gibbes has founded his genus ^^Dorudon^ It reminds me of the character 

 of the serrated teeth described by M. Grateloup in the " Jahrbuch fiir Mineralogie," 

 1841, p. 830, as those of a fossil carnivorous cetacean for which he proposes the name 



* Fossiles de St. Pierre a Maeslrecht. PI. XLIX.. k. 

 3 



