4:2 ANNALS NEW YORK ACADEMY OF SCIENCES 



marked difference in the strength of the subordinate spirals and in the 

 more angular outline of the adult volutions, but the shell agrees with the 

 description and figure in essential respects. Its early development and 

 the general character of its adult features show it to belong undoubtedly 

 to the Cerithium tuberosum group. 



Cerithium glaphyrea Dall 



1892. Cerithium glaphyrea Dall, Trans. Wagner Free Institute of Sci., Phila., 

 Ill, pt. 2, p. 283, pi. 14, fig. 4. 



Measubements (Dall) : Length, 16 mm. ; greatest diameter, 6 mm. ; Remain- 

 ing MEASUREMENTS FROM FIGURE : Apical angle, 23° ; sutural angle, 88°. 



JSlo specimen of this species has been obtainable, but from the original 

 description and figure the following features of interest in this connection 

 may be determined. From the figure it apj)ears that the shell has two 

 spirals stronger than the others, with fine spirals between the two primary 

 ones and on the shoulder. A third strong spiral on the shoulder becomes 

 nodose, but is not so strong as the two main spirals. All the spirals are 

 crossed by numerous closely set ribs. The two strong spirals remain of 

 equal strength and continue to form an oblique angle for the whorl until 

 the body volution is reached, when the lower of the two becomes weaker. 



The aperture is of the type usual in the Cerithium tuberosum group, 

 with a narrow callus and strong posterior tooth, flaring, crenulated outer 

 lip and short anterior canal. 



Horizon and ix)cality : Pliocenic of the Caloosahatchie beds, Florida. 



Eemarks : This species has a strong fundamental resemblance to Ceri- 

 thium callisoma in the form of the body and of the aperture, and in the 

 persistence of the oblique-angled outline of the whorls formed by two 

 strong spirals with a weaker one on the shoulder. The most striking dif- 

 ference is in the very numerous ribs of C. glaphyrea, which are so closely 

 set as to appear like rows of nodes where crossed by the coarser spirals. 

 C. glaphyrea appears to have the essential characteristics of the C tuber- 

 osum group, but probably represents a lateral branch from the main line, 

 expressing its divergence in the development of numerous ribs. 



Cerithium glaphyrea mut. litharium Dall 



1892. Cerithium glaphyrea var. litharium Dall, Trans. Wagner Free Institute 

 of Sci., Phila., Ill, pt. 2, 284, pi. 14, fig. 9. 



Measurements (Dall) : Length, 19 mm.; greatest diameter, 6.5 mm. 



