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SUPPLEMENT TO THE CRAG MOLLUSCA. 



to have been warm. Further, we have the following sixteen Cor. Crag genera not yet 

 known to be living in the seas of Britain, of the North Atlantic, or of the arctic regions, viz. 

 Panoj)ea} Pholadomya, C/iama, Hinnites, Erycinella, Scintilla, Nucinella, Lingula (?), 

 S/garetus, Pyramidella (?), Fossarus (?), Cancellaria (rejecting Aclmete) , Cassidaria, Terebra, 

 Pgr/da, and Volula, to which might be added a section of Pleurotoma, and but for the late 

 dredgings in abyssmal waters, the genus Verticordia also. The presence of these genera 

 in the Coralline Crag seem to me to impart a more southern aspect to its fauna than any 

 analysis of the species themselves would do. 



There are a few forms both in the Coralline and in the Red Crag, the living 

 analogues of which survive in seas so remote as to throw no light on the affinities 

 of the faunas of those Crags. Of these in the Cor. Crag the little Erato, which 

 I had identified with the West Indian species Maugeria, may be instanced. 

 Mr. Jeffreys, however (in a letter), informed me that he thought the specimens in 

 my collection (in the Brit. Mus.) might be stunted forms of lavis. I believe, however, 

 that E. Maugerics is identical with the shell from the Cor. Crag figured by me under that 

 name. I have compared many specimens of each without being able to detect a difference 

 that might be called specific, or any more difference than may be observed among the 

 specimens themselves, and I cannot consent to degrade my little Crag shell into the 

 position of a variety, as it and the true Icevis are found together at the same spot without 

 intermediate forms. 



The characteristic shell of the newer part of the Red Crag, of the Fluvio-marine Crag, 

 of the Chillesford bed, and of the Lower, Middle, and Upper Glacial deposits, Nucula 

 Cobboldia, is another of these instances ; the living analogues of this shell, of which there 

 are two or three, being denizens of the North Pacific ; and although I have pointed out 

 in the body of this ' Supplement ' the characters which seem to me to distinguish Nucula 

 Cobboldia specifically from all these allied species, yet it is very remarkable that its 

 analogues should be several in number, and all of them confined, as far as yet is known, 

 to so remote a sea. 



In 1838 Mr. Conrad published figures and descriptions of some Medial Tertiary 

 fossils of the United States bearing a strong resemblance to Crag forms ; and in a paper 

 upon these, published in the 'Proceedings of the Geol. Soc.' for the year 1843, Sir 

 Chas. Lyell gives the names of several species that he considered to be identical with 

 Crag, or, at least, with European fossils. 



In the ' Geological Magazine ' for April, 1865, vol. ii, is a communication by Dr. P. 

 Carpenter upon the connection between the Crag and the recent Mollusca of the North 

 Pacific, wherein he appears to consider the Crag fauna and the North Pacific fauna to 

 have emanated from the north, the one diverging eastward and the other westward. He 

 says at p. 153, " Not taking into account similar forms, no fewer than twenty-four species 



1 Panopea Norveyica does not properly belong to the genus Panopea, but perhaps to Panomya ; see 

 p. 101 of this Supplement. 



