42 Frederlch Chapman : 



the crown nearly, if not quite, equal in length to the root, and the 

 enamel furrows are sharply ridged and not vermiculate, as in the 

 above species. 



The smaller and slender character of the tooth and the closed root 

 resembles that of the Dolphin family, and comparison was made 

 with Delphi/ius uncichns, Lankester,!! which, although having the 

 peculiar twisted and swollen shape of the root of the Beaumaris 

 tooth, has the enamel of the crown finely and sparsely furrowed. 

 Turning, then, to Prof. Flower's classical paper " On the Characters 

 and Divisions of the Family Delphinidae,"2 we read that the genus 

 Stetio, Avhich is rei^resented by S.rostratvs, Cuvier sp., and found in 

 the Atlantic, Indian and Pacific Oceans, and in the Red Sea, is 

 distinguished from other genera of this family by the furrowed 

 character of the teeth : — " Teeth, 21 to 25 on each side of the jaw, 

 of comparatively large size (5-6 millims at base of crown), ^ 

 and in most, if not all the spec'ies, with their surfaces roughened by 

 fine, irregular longitudinal grooves (which are in a great measure 

 effaced in old individuals), not seen in other Dolphins, and whence 

 the name Gh/phidelphis proposed by Gervais for the section."'* 



Occurrence. — Tertiary (Kalimnan), Lower Pliocene. Beaumaris, 

 Port Phillip. Found by Mr. F. A. Cudmore, after whom it has been 

 named, and who presented it to the National Museum. 



EXPLANATION OF PLATES. 

 Plate IV. 



Fig. 1. — MesopIodoN comp7'essus, Huxley sp. Cranial rostrum, 



viewed from above. Specimen A. Tertiary (Kalimnan.) 



Grange Burn, near Hamilton, Victoria. About 'i natural 



size. 

 Fig. 2. — M.comj^ressus, Huxley sp. Cranial rostrum, viewed from 



the side. Specimen A. About i- natural size. 

 Fig. 3. — M.compressus, Huxley sp. Cranial rostrum, viewed from 



below. Specimen A. About f natural size. 

 Fig. 4. — M.compressus, Huxley sp. Cranial rostrum, viewed from 



above. Specimen B. Same locality. About '^ natural 



size. 



1 Ann Mag. Nat. Hist , ser. 3, vol. xiv., 1864, p. 350, pi. viii., fisfs. 12, 13. This tootli and 

 otic bones have since been referred to the genus Globieephalvs. See TiVdekker. Cat. Foss. llani- 

 nialia. Brit. Mu.s., pt. v., 18S7, p. 81. 



2 Proc. Zool. Soc. Lond., 1883, pp. 466-513. 



3 Width of crown in fossil specimen, 4 nun. 



4 Op. supra cit., p. 482. 



