BY H. H. SCOTT AND CLIVE E. LOUD. 7 



Avell as being an extremely valuable Museum exhibit. (See 

 Plate No. I.) 



PSEUPORCA CRASSIDENS. 



General osteological notes upon the Tasmanian skele- 

 ton, and a comparative table of measurements of the larg- 

 est, lumbar vertebree of that skeJeton, with Reinhardt's 

 male from Middlefart. 



The skull in a wide sense is that of a small "Orca," and 

 the teeth conform to the Orca type, in having recui*ved 

 crowns, but of course are much smaller, as indicated by the 

 following comparison with a true Orca's teeth, measured 

 directly for this special purpose. 



The parietal, and squamosal moieties of the fcssse tem- 

 poralis in the Pseudorca are quite imlike those of Orca, 

 being compounded in the following way. The squaimosal 

 contributes a narrow practically, even strip, about 2 inches 

 wide, set at an angle, and continued to near the vertex. 

 In the Orca the squamosal is wide, and irregular, and takes 

 a larger share in the formation of the fossa (upon either 

 side). One Orca skull, however, in the Museum collection, 

 makes a nearer approach to Pseudorca in this respect. The 

 parietal wings of Pseudorca are bent backwards at a slight 

 angle, to the line of the skull, exactly as in Tiirsiops, 

 while in the Orca, the whole boundary waJls of these fossse 

 bend outwards, as continuous outgrowths of the occiput. 



In the skeleton it may be noted that five of the cer- 

 vical vertehrce are strongly ankylosecl together, and two are 

 quite free. 



A meta.pophysis appears- — faintly indicated — upon 

 the second dorsal, and well marked one upon the fourth. 

 The seventh dorsal develops these processes at the upper 

 level of the neural arch, in other words at the base of the 

 neural spine. Unlike the smaller dolphins, these i^rocesses 

 are not eliminated from the vsrtebrse in the region of the 

 dorsal fin, but continue to gradually decrease after the 



(9) This is ex-alveolar, enamel surface measurement. 



