﻿ADDENDA. 



201 



The Syrian examples possess equal variability, and occasionally have the costae not 

 less prominently tuberculated : the typical form has the marginal carina? always more 

 strongly defined, and the siphonal border more lengthened, than the variety arata. 



Trigonia undulata, From. Locality, the Lebanon east of Beyrout. 



Mr. Damon, of Weymouth, who obtained the Syrian fossil, informs me that 

 specimens are found at three localities near Abich : one in the village itself in a loose 

 earth south of the village, 2400 feet above the sea ; the best locality is two miles 

 distant to the south-west at an elevation of 2000 feet ; the third locality is directly east. 



Trigonia spinosa, Park., var. sdbovata. Page 136, Plate XXIII, fig. 10; Plate 



XXVIII, figs. 1, 2. 



In the Upper Greensand of the Isle of Wight, T. spinosa occurs in the defective 

 condition common to the Testacea of that formation ; occasionally the test is partially 

 preserved, and the costae with their obtuse spines are more or less distinct. Usually the 

 species is represented by a variety which also occurs not uncommonly in the Upper 

 Greensand of Wiltshire, where it has undergone compression, and the moulds of 

 external casts have the surface ornaments only obscurely visible. The Isle of Wight 

 specimens sometimes have the surface better preserved, and the moulds are more free 

 from compression. PI. XXIII, fig. 10, represents a small specimen, the only one having 

 the test preserved and uncompressed with which I am acquainted. Compared with the 

 typical form (PI. XXIV, figs. 8, 9), the convexity near the umbo is more considerable; 

 the pallial costae are somewhat more straight and are directed more towards the lower 

 border ; the costellae upon the area are much decussated by the lines of growth, the 

 costellae also are directed more posteally or towards the siphonal border ; both the costae 

 and costellae are therefore less radiating, and have somewhat less curvature ; the general 



