Paleontology Zorritos Formation 65 



T. reversa Waring/^ from the Martinez Eocene of Cali- 

 fornia, is apparently so close that there is possibility of 

 identity, but the figure of reversa is too poor, and the descrip- 

 tion too inadequate to allow a decision, and the matter must 

 be held in abeyance pending comparison of material, with the 

 possibility in mind that reversa may be a synonym. 'Bhe 

 only difference notable is that the shoulder appears stronger 

 in bifastigata. Waring compares his species with T. hum- 

 erosa Conrad,^^ from the Eocene of Maryland, and if the 

 similarity exists reversa may be quite different from bifas- 

 tigata^ for humerosa differs materially. 



T. concava Hutton,^^ from the Miocene of X'ew Zealand, is 

 ver}- close, but has a wider apical angle, and the posterior 

 shoulder is not as prominent as in bifastigata. There is a 

 submedian ridge on the whorls of concava which is certainly 

 not present in bifastigata. 



Upper Zorritos. Quebrada del Toro. 



Tiirritella filicincta Gryzbowski 



Plate III — Fig. 2. 



Turritella tiliciiicta Grzybowski, Neues Jahrb. f. Min. etc., B.B. 

 12, p. 645, pi. 20, fig. 2, 1899. 



"Die conischen Windungen sind dicht iiber der Xaht mit 

 scharf nach unten abgeschnittenem Kiel versehen. Die ganze 

 Oberflache is mit iiberaus feinen Spiralleistchen gezeichnet, 

 die dicht beieinander liegen. Es stehen deren 26 auf einen 

 Raum von 5 mm. In dem oberen Telle der Windungen sind 

 sie ziemlich gleich, in dem unteren dagegen liegt immer ein 

 starkeres Leistchen zwischen zwei schwacheren. An der 

 Basis verlaufen 4 Spiralrippen, die auch mit den feinen 

 Leistchen bedeckt sind." — Grzybowski, 1899. 



Proc. Cal. Ac. Sc, 4th ser., vol. 7, p. 88, pi. 12, fig. 15, 1917. 

 Md. Geol. Surv., Eocene, p. 148, pi. 27, figs, i, la, 1901. 

 New Zeal. G. S., Pal. Bull. 3, p. 7, pi. 5, fig. 4, 1915. 



