DiPL. 



206 



fe 



Dipleura dehayi. See Homalonotus dekayi. Villi), c. 

 Diplodus -fish teeth. Dawson's Acad. Geol. 1868, p. 211, 



fig. 57, Diplodus penetrans from the Pictou 

 Diplodus, A / I ^^^^ mines ; and fig. 58, Diplodus acinaces^ 



from the roof shales of the Main coal at 

 Pictou, N. S.—XIII. 



Diplodus ? -fish toothy from the Upper Barren coal measure 

 (Washington Middle) limestone No. 4. of the Washington 

 County Group, in Prof Adney's collection at W. & J. College; 

 a fragment from the middle layers of the limestone. Steven- 

 son searched in vain for other examples ; but the lower layers 

 in the RR. cut to first tunnel east from Claysville yielded a 

 Ush spine ; and Prof. Jones has a fine spine from a boulder of 

 the same. (K, p. ^9,)— XVI, 



Diplograptus (Graptolithus) angustifolius, Hall Pal. N. 



Hall, II!. ^' ^^^' ^? P* ^^^'> w<^o^ cut %• 1^ a single 

 D.a. stipe, twice the natural size; fig. 2, a portion 

 still farther enlarged. The midrib projects 

 beyond the serrated portion like a single hair. 

 / The saw teeth (serratures) are arranged in 

 M \ ■ '^ / the proportion of about 28 to 30 in the space 

 ij V" ^/ ^f ^n inch. Portions of the teeth differ from 

 y those of any other species in the formation, 

 Ci_jl/ and often are more like those of fossil ferns, 

 ^ - and are not always quite opposite to each 



other. Hudson River slate,, IIIl). 



Diplograptus (Graptolithus) marcidns. Hall, Pal. N. Y. 

 ,„^ J ^4^,, ,„ vol. 3, p. 514, 515, wood cuts, 1, a specimen 



Ad. rn. more contracted than usual, with blunt teeth ; 

 I \ \ 2, one more expanded, with distinct teeth at 



the lower end and a minute radical below ; 3, 

 a young form with teeth undeveloped or flat- 

 tened in the line of their direction, and 

 minute fibres or radicles at the base well pre- 

 m served. Species not absolutely well deter- 

 ''^^" J mined. This and D. angustifoUus, G, whit- 

 Heldi,, G, spinulosus, and Reteograptus gein- 

 itzianus. are found together near Albany in Hudson River 

 slate^ III J), 





s 



