1888.] NATURAL SCIENCES OF PHILADELPHIA. 163 



of Miiller and Henle. He gives as characters of the dentition, 

 " upper first tooth not smaller than the second ; one or two small 

 teeth between the upper third and fourth long teeth ; large teeth 

 with a single small cusp on each side. As localities, he gives the 

 Atlantic and South Pacific. 



Jordan and Gilbert, in the Synopsis of the Fishes of North Amer- 

 ica, for Odontaspiti littoralis, also include all the other names men- 

 tioned as synonymous except the 0. taurus. As distinctive characters 

 they adopt the diagnosis of Evgomphodus of Gill — "first and fourth 

 teeth of the upper jaw and first of the lower simple, without basal 

 cusps. " Miiller and Henle gives as characters of Odoiitasjjis taurus 

 " upper first tooth smaller ; then follow two very long teeth ; then one 

 or two smaller ones ; then again large ones from which they grad- 

 ually decrease. The lower teeth gradually decrease from the second." 

 Besides the specimen of Odontaspis littoralis from Beesley's Point, 

 we have at command half a dozen sets of jaws of the same species. 

 Of these one is from Nantucket, and another from Townsend's Inlet, 

 N. J. ; the others have no locality marked. In all the essential 

 characters of the dentition are alike ; but they do not accord with 

 those w'hich have been given as distinctive of the species. The 

 number of teeth varies according as there are a few or more of the 

 rudimentary ones at the ends of the series, but this is a difference of 

 no diagnostic value as a like variation occurs on the two sides of the 

 same jaw. In all our specimens, without exception, the teeth are 

 provided with a pair of denticles ; none being simple as intimated 

 by Gill, and by Gilbert and Jordan, in the diagnosis of Eugompho- 

 dus. The anterior teeth in general are long, narrow, and sigmoid, 

 and their denticles are curved. The more posterior, lateral and 

 larger teeth are shorter than the former and proportionately wider, 

 and have also shorter and wider denticles. In different specimens 

 they exhibit a variable disposition to the production of a second 

 smaller denticle. In five of the sets of jaws in which the teeth are 

 well displayed throughout, we find the following range of numbers : 



19—17, 19—22, 2 0—18, 22—23, 24—24. 



18—18 18—17 18—14 19—19 22—24 

 The distinctive dental characters are as follows : — In the upper 

 jaw, three large teeth, of which the first and third are nearly equal 

 and the second is slightly larger; fourth tooth very small, about 

 one third the size of the former ; then follows a considerable hiatus ; 

 fifth to the seventh teeth nearly equal and smaller than the third 



