157 



types of this group in Great Britain ; and in the Elements of Ge- 

 ology, by Mr. Lyell, it is also said that in England the Miocene 

 strata are wanting, the Tertiary being limited to the Eocene and 

 the Pliocene. In the Principles of Geology, edition of 1842, the 

 Coralline Crag of Suffolk, and the Red Crag, succeeding, two ex- 

 tensive deposits, are both ranked as belonging to the strata, said in 

 the other cases to be wanting — the Miocene. Now there is nothing 

 to show in this last published edition why the author makes a state- 

 ment so different from that in his Elements and in other works. 

 The reader of these only, is therefore left in doubt as to the cor- 

 rectness of either. A satisfactory explanation is, however, con- 

 tained in an address delivered by Prof. Buckland before the Geolo- 

 gical Society of London, in 1840. An account being there given 

 of a visit made by Mr. Lyell to Norfolk and Suffolk, for the pur- 

 pose of determining, with the assistance of others who accompanied 

 him, the age of the deposits there, by a comparison of their fossil 

 shells with the recent. It was found that the number of extinct 

 species, in both the Coralline and Red Crag, brought them both 

 within the limits of the Miocene, and that the views before held by 

 geologists had been erroneous. 



Dr. Storer read extracts from a letter of Mr. S. S. Halde- 

 man, as follows: — "I have a third undescribed species of 

 Percina. from the Susquehaimah. which may be charac- 

 terized as follows/' 



" P. bimaculata. Light yellow, sides transversely and irregularly 

 branded with black, and dorsal fins clouded with brown, a distinct 

 black spot at the extremity of the lateral line. Slender, lateral 

 line sub-rectilinear, above the middle ; ten or twelve irregular trans- 

 verse bands upon the back and side ; rays of the second dorsal and 

 caudal fins crossed by bands of dark brown. 



D. 15— 15 : P. 13 : V. 6 : A 11 : C 17. 



The length of the pectoral fins deserves mention as a generic cha- 

 racter." 



Dr. Gould read descriptions of shells received from Drs. 

 Savage and Perkins, from Africa. They are as follows: — 



Helix (Caracolla) pellucida. Testa fragili, pellucida, pallide 



