Guppy Reprint 



i43 



tions, thus dividing the back into three parts, the median par 

 bearing a single row of distant, low, but acuminate tubercles ; 

 and each lateral portion two rows of similar tubercles somewhat 

 irregularly arranged. The length of the specimen is about 5 cen- 

 timetres by 4^ centimetres in extreme width. 



A specimen of Ranina collected by me from the Naparima 

 rocks was described by my friend Dr. Henry Woodward, F.R.S., 

 in 1866, under the name of R. porifera, (Jour. Geol. Soc, Vol. 

 XXII, p. 591.) Dr. Woodward gave a list of all the species of 

 Ranina then known to him, eleven in number, of which ten were 

 fossils from tertiary deposits, and the remaining one is a living 

 species found in Japanese and Eastern seas. I am not aware of 

 any additions having been made to Woodward's list. I am un- 

 able positively to allege that our present species is different from 

 that described by Woodward, inasmuch as in the latter the super- 

 ficial characters of the Carapace are preserved whereas in the 

 present specimen the shell has disappeared. R. porifera also 

 lacks the frontal margin so that we do not know what the form 



Page 56 



of it was, while in R. cuspidata the frontal margin is almost per- 

 fect. Further, the dorsal surface of R. porifera is free from 

 tubercles. 



The occurrence of Ranina in the tertiary rocks of Trinidad 

 is another fact to be added to those noticed in my Paper on the 

 "Geological Connexions of the Caribean Region," showing the 

 probable connexion by sea between the Caribean Sea and the 

 Pacific Ocean at a former epoch. 



The concentrically-ribbed bivalve referred to in the forego- 

 ing Paper is probably Venus bla?idiana, Guppy, (Proc. S. A. 

 Trim, 1873, page 85. PI. II, F. 8 ; Geol. Mag. 1874. PI- XVII, 

 F. 8). It is said by Dall, Florida Fossils, Part VI. page 1277) to 

 be like his Cytherea strigilina, but I do not know that species. 

 It is like V. versafi/is, Dolf., Faluns of Touraine (Journ. Conch. 

 1888, PL XII. F. 4). 



