FOSSIL FINBACK OF GAY HEAD. 285 



they ranged is yet to be discovered, but no doubt they were commonest in the near-shore waters 

 as far at least as the present Carohna coast. Associated with the whale bones, have been 

 found remains of a walrus similar to the existing species, a fact that further indicates somewhat 

 boreal conditions. 



Economic Value of the Bone-bearing Strata. 



The possible commercial value of the bone-containing beds at Gay Head is commented 

 on by Shaler (7th Ann. Rept. U. S. Geol. Surv., 1888, p. 357). The fragments of bone, are so 

 intermixed with quartz pebbles, that it seems doubtful if the beds can be advantageously 

 worked for the production of phosphates. He adds: "One of the most promising portions 

 of this section lies at the northern end of that part of Gay Head escarpment which faces about 

 west. It is about one hundred feet in thickness and consists of dark greenish-gray sands and 

 clay, which in part are somewhat oolitic in structure. These beds contain a considerable 

 quantity of cetacean bones. They also contain a certain amount of phosphatic nodules which 



vary in size from a tenth of an inch in diameter up to five or six inches Both the nodules 



and the fragments of bone, as remarked by Dr. Hitchcock, have probably been derived from 

 pre-existing strata, the debris of which makes up this part of the section." Professor Shaler 

 gives the following chemical analysis of the fossil cetacean bones: 



Phosphoric acid (P2O5) . . 27.S0 



Carbonic acid (CO2) 3.28 



Lime (CaO) 27.21 



Potash (K2O) 0.97 



Soda(Na20) 0.56 



Descriptions. 



Cope's original description of Balaenoptera sursiplana has to do with the tympanic bone 

 of the ear only, wliich, he wrote, differs from that of other species of the genus in the "con- 

 vexity of the superior face where the dense layer or lip has a different chord or face from that 

 of the space which separates it from the internal longitudinal marginal angle. In the B. sursi- 

 plana there is but one superior plane from the eustachian orifice to the internal edge, which is 

 absolutely flat. In all these species also the dense layer of the lip is reflected on the superior 

 edge of the external thin wall at its anterior end. In the present species this layer is reflected 

 in a very narrow strip underneath the free border, which overhangs it. In all these species also 

 the anterior extremity, as viewed from above or below, is angulate, the angle marking the end 

 of the inner border of the dense layer or lip. In B. sursiplana the anterior extremity, viewed 

 in the same way, is truncate. The species which appears to approach nearest is the B. definita 

 Owen In size this species is like that of the large Balaenopterae." The measurements 



