121 



Obs. This very rare British, fossil occurs in the Portland 

 Bands at Gad-cliff, near Kimmeridge Bay; there is no other 

 record of it in any other British locality. It is not, however, 

 uncommon on the other side of the Channel. Dr. Lycett's 

 figure in the Palseontographical is taken from the unique 

 Dorsetshire specimen, which is now in the National Museum 

 of Practical Geology. Dr. Lycett says of it, " The minuteness 

 and delicacy with which the character of the surface has been 

 preserved leave little cause to regret the absence of the test." 



TRIGONIA PELLATI, Ifun. Chal., plate ii., fig. 4. 



MONO. BBIT. Foss., TRIGONLZE, Lyc. y Pal. Soc., p. 41. plate vii., 1, 2 a.b., 

 plate ii., fig. 1. 



Shell oblong, inordinately elongated, the superior border 

 wide, the inferior depressed, and wedge-shaped; umbones 

 near to the anteal extremity of the valves, obtuse, much incurved, 

 and depressed ; anterior side very short, truncated, with con- 

 siderable convexity, its border curved elliptically with the lower 

 border, which is very long and straight ; the superior border is 

 also very long, its border slightly concave, its posteal extremity 

 forming an obtuse angle with the posteal border of the area and 

 terminated with a somewhat pointed and much produced 

 extremity ; the area is long and slightly convex with a well- 

 marked mesial furrow, bordering a line of minute tubercles, and 

 bounded by two delicately traced and minutely tuberculated 

 carinse ; escutcheon flattened, of moderate breadth, but unusually 

 lengthened. The sides of the valves are very narrow, and have 

 a few rows of very distinctly arranged oblique tuberculated 

 cost&e. Three or four of the tubercles nearest the carinse are 

 larger, rounded, and pointed. This is the most elongated of the 

 ClavellatoB. 



Obs. T. Pellati occurs frequently in the Lower Beds of the 

 Kimmeridge Clay series at Kimmeridge Bay. The specimen 

 figured by Dr. Lycett came from thence ; and is deposited in 

 the National Museum of Practical Geology, Jermyn-street. 



