84 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



23. Lytoceras (Tetragonites) cala (?) (Forbes) StoUczka. 



cf. Ammonites cala Forbes, Trans. Geol. Soc. Lond., Ser. II, Vol. VII, 



1845-56, p. 204. 

 Ammonites cala (?) (Forbes) Stol., Pal. Ind., Vol. I, p. 153, PI. LXXV. 



In the collections of Lorenzo G. Yates, temporarily^ 

 deposited at Stanford University, are several specimens of 

 a Lytoceras of the genus Tetragonites, which appear to be 

 referable to L. cala, as described by Stoliczka. They 

 have been compared with both Forbes' and Stoliczka's 

 figures, but so far as can be ascertained by this means they 

 agree more nearly with the latter. They are from the 

 Arroyo del Valle, eight miles southeast of Livermore, Ala- 

 meda County, California. 



In all respects they agree perfectly with Stoliczka's 

 description. The shell is evidently a close relative of 

 Forbes' species, which could be distinguished from it onl}^ 

 by a comparison of types. 



Shell discoidal, flattened on the sides, and of a diameter not exceeding 

 7.6 cm.; umbilicus wide and shallow, with abrupt walls; involution very little, 

 clasping little more than the flattened ventral surface; shell increasing slowly 

 in size with growth; section of whorls tetragonal; suture consists of three 

 lobes on each side, with auxiliary lobes much reduced, upon the umbilical 

 surface. The siphonal lobe is broad, divided by a denticulated tongue- 

 shaped siphonal saddle. 



Occurrence. — There are in the Yates collection four or 

 five specimens of this shell, all of which have been obtained 

 from the Jordan ranch on the Arroyo del Valle, eight miles 

 southeast of Livermore, Alameda County, California. The 

 horizon is that of the Lower Chico. Stoliczka says L. cala 

 is from the Ootatoor beds of India. 



24. Lytoceras bates! (Trask) Gahh. 



Under the specific title of Ammonites hatesi Gabb included 

 three quite clearly marked species which he recognized as 

 only varieties. In all the larger collections of Cretaceous 

 fossils in California there are numerous specimens of 

 related forms bearing this name. The confusion is the 



