TRANSACTIONS OF WAGNER 



TERTIARY FAUNA OF FLORIDA 



This little shell is rare in the marl, and resembles in a general way C. 

 divaricata Orb., of which it is the precursor, but has fainter sculpture and 

 smooth beaks, besides being constantly of smaller size, and is more narrow in 

 form than the young of C. divaricata of the same length. 



Crenella duplinensis n. s. 

 PLATE 35, FIGURE 6. 



Miocene of the Natural Well, Duplin County, North Carolina; Burns. 



Shell small, thin, rounded ovate, delicately radially sculptured, with fine, 

 rounded ribs crossed by delicate incremental lines ; smoother towards the 

 beaks ; valves moderately inflated ; beaks recurved, stria; diverging from a 

 line near the anterior third ; inner margin crenulated, the crenulae extending 

 well up into the valve; the hinge with its crenulations short and delicate. 

 Alt. 2.9, lat. 2.4, diam. 1.5 mm. 



This species is proportionally wider and less inflated than C. minitsaila, 

 attains a larger size, and has more recurved beaks. From C. divaricata it 

 differs by its feebler sculpture, somewhat smaller shell, and especially by its 

 much weaker hinge, with less conspicuous and strong crenulations. The line 

 of divarication of the sculpture is also more anterior and the beaks more 

 recurved. 



The recent Crenella glandula Totten is reported as fossil in the Pleisto- 

 cene beds at Montreal by Dawson (Geol. Rep. Can., 1863, p. 927), and at 

 Sankoty Head, Massachusetts, by Verrill, But Dr. Dawson is now disposed to 

 refer his specimens to C. faba Fabr. 



Genus MODIOLARIA Beck. 



Modiolaria Beck, in E. Robert, Zool. Voy. Recherche en Isl. et en Gronl., pi. 17, figs. 1-4, 



1840; Loven, Ind. Moll. Scand., p. 33, 1846. Type Mytilus discors Linne. 

 Lanistcs Swainson (as of Humphrey), Malac., p. 385, 1840 ; not of Montfort, 1810. Type 



Mytilus impactus .Herrmann. 



Lanistina Gray, P. Z. S., 1847, p. 199 (in place of iMiiistcs Sw.). 

 Modiolacra Gray, in Dieffenbach, N. Zeal., ii., p. 259, 1843 ; fide Hutton, Cat. Mar. Moll. 



N. Zeal., p. 78, 1873; (a typographical error for Modiolaria?) sole ex. M. impacta 



Gray. 



Swainson quotes Lanistcs as of Humphrey, but there is no such genus in 

 the Museum Calonnianum, where the Mytilus discors Lam. (not of Linne), 

 otherwise M. impactus Herrmann (1776), is given the specific name of 



