1914] Dickerson: Fauna of the Martinez Eocene of California 129 



CUSPID AEIA HANNIBALI, n. sp. 

 Plate 9, figure 10 



Shell small ; beaks subcentral, of medium size, approximate,-promi- 

 nent and slightly curved anteriorly. Posterior end is about one-third 

 the height of the shell and is produced. The posterior portion of the 

 shell is marked off sharply from the anterior by four transverse 

 rounded ribs which extend from the beak to the base. The interspaces 

 are somewhat wider than the ribs. In two of these interspaces a riblet 

 is found. These ribs do not extend to the posterior tip but end where 

 the posterior portion suddenly narrows, thus dividing the shell into 

 three distinct parts. The anterior portion is rounded and its base is 

 regularly convex. The anterior portion is marked only by concentric 

 lines of growth. A sharp ridge extends from the beak to the dorsal 

 edge of the posterior end and a sharp groove is found between the 

 hinge line and this ridge. Interior unknown. 



Dimensions. Length, 10 mm. ( ?) ; height, 5 mm ; width of produced 

 anterior portion near ribs, 2 mm. 



Occurrence. University of California Locality 1547, Martinez 

 Group, Trochocyathus zitteli zone. 



This specimen differs from Neaera dolabraeformis Gabb, which is 

 reported from his "Cretaceous B," in the following ways : (1) Its beak 

 is far less prominent. (2) Its ribs are confined to the central third 

 of the shell, only, while the radial ribs of N. dolabraeformis cover all 

 the shell but the produced posterior end. (3) N. dolabraeformis lacks 

 the prominent ridge extending from the beak to the anterior end. 



This specimen was found by Mr. Hannibal, who accompanied the 

 writer to the locality. The species is associated with Trochocyathus 

 zitteli, Pholadomya nasuta, Urosyca caudata, Cucullaea mathewsonii, 

 Glycimeris veatchii, var. major and Cardium cooperi. 



Named in honor of Mr. Harold Hannibal. 



CRASSATELLITES STUDLEYI, n. sp. 



Plate 10, figure 1 



Shell thick, high, suborbicular ; beaks prominent, prosogyrate, 

 moderately high, approximate, and situated back of mid-length. Pos- 

 terior dorsal margin slightly convex, sloping to the broadly rounded 

 posterior end. A well-marked, narrow escutcheon is set off by two 

 acute ridges from the rest of the shell. Anterior dorsal margin nearly 



