i3° 



HARDWICKE'S SCIENCE-GOSSIP. 



preserved. Mr. F. J. Millet* has published a list of 

 upwards of one hundred species obtained by him. 

 We can strongly recommend this clay to microscopists. 

 A most striking feature in the mollusca is the large 

 number (49) of Mediterranean species, indicating a 

 more direct connection with that sea than now exists. 

 Of the species, 37 occur in the coralline crag, 33 in the 

 lower red crag, 23 in the upper red and Norwich crag. 

 The following table shows some of these relations, 

 and I have also added for comparison, the mollusca 

 from the coralline and red crag, on the authority of 

 the late Mr. S. V. Wood.f 



Coral- 

 line 

 Crag. 



Walton 

 Naze 

 Red 

 Crag. 



Re- 

 mainder 

 of Red 

 Crag. 



Total number of species) 



of mollusca . . . .) 

 British and not Mediter-'i 



ranean species . . .j 



Mediterranean and British 



,, and not\ 



British J 



Neither Mediterranean! 



nor British . . . . j 

 Species not known living 



39* 

 20 



154 

 51 



24 

 142 



148 



'3 



61 



14 



10 

 5° 



199 



3° 

 78 

 14 

 22 



55 



St. Erth 

 Clay. 



about 

 92 



6 



41 



8 



36 



35 



The following occur which are absent from the 

 Suffolk crags, and are characteristic Mediterranean 

 forms : Fusus comeus, A T assa mutabilis, Ca)'ditun papillo- 

 sum, Carditaaculeata. The absence of Fusus antiquus, 

 F, gracilis, Buccinum dalci, and B. undatum, which 

 are abundant in the Suffolk red crag, is remarkable. 

 Littorina subaperta, Conovulus pyramidalis, Nassa 

 granulata, and Columbella sulcata, occur, and form an 

 important connecting link with the red crag. From 

 such facts as these Messrs. Kendall and Bell infer 

 u that, at the period of which we are writing, no 

 channel of direct communication existed between the 

 North Sea and the Atlantic Ocean, the Straits of 

 Dover in the south being closed, while on the north- 

 west the Tertiary volcanic chain threw a barrier 

 across from the north of Scotland to Greenland, 

 by way of the Shetland and Faroe Islands and 

 Iceland." 



"The study of the present configuration of the 

 North Atlantic is strongly confirmatory of this opinion. 

 The 100 fathom line encloses the Orkneys and Shet- 

 lands, while a long submerged ridge with deep water 

 upon each side extends from the Hebrides to the 

 Faroe Islands and, as has been so fully explained by 

 the late Dr. Jeffreys, has had a great influence in pre- 

 venting the intermingling of the marine faunas upon 

 each side of it." 



The facts against this theory are chiefly limited to 

 the occurrence at St. Erth of Cardium clcgantuhim, 

 which does not live farther south than Norway, and 

 of Conovulus pyramidalis, which occurs only in the 



* Royal Geol. Soc, Cornwall. 



"t Crag Mollusca. (Palaeontogrjph. Soc, 1874.) 



crags of East Anglia, and in the glacial deposits of 

 Wexford. 



Most authorities seem agreed as to the age of these 

 beds, with the exception of Mr. Clement Reid,* of the 

 Geological Survey, who correlates them with the 

 Lenham beds, which are probably of Lower Coralline 

 Crag age. And we must confess that the 37 species 

 occurring in the Coralline Crag, against only 33 in 

 the Lower Red Crag, does seem in favour of this ; 

 nevertheless, this numerical method of correlation is 

 not altogether free from objection. Mr. Reid also- 

 considers the depth at which the clay was deposited 

 to have been from forty to fifty fathoms ; but Mr. 

 Bellf cannot agree with so great a depression, the 

 shells in his opinion indicating a much shallower 

 sea. 



It is to be deplored that our three chief authorities 

 on the Mollusca of this period have recently passed, 

 away. Dr. Gwyn Jeffreys, Mr. Searles V. Wood, jun., 

 and Mr. Robert G. Bell, had each commenced an 

 examination of the St. Erth mollusca. Writing on 

 this deposit in the " Geological Magazine " for October 

 last, Mr. Bell says : — 



" It is hoped that a more detailed examination of 

 the molluscan fauna may soon be completed, and the 

 whole series added to the national collection." 



But it was not to be. 



For those who wish to go further into this subject,, 

 we would refer them to the papers above mentioned, 

 more especially to the excellent account by Messrs- 

 Kendall and Bell. X. 



NOTES ON THE EIGHTH EDITION OF THE 

 LONDON CATALOGUE OF BRITISH 



PLANTS. 



By Arthur Bennett, F.L.S. 



[Continued Jrom page no.] 



1517, added species gathered in Norfolk by my 

 daughter and myself; its first record in Britain. 

 N. minor ought to occur, it is somewhat like N. 

 Jlexilis. 



1518, added species from a canal near Manchester,., 

 perhaps brought with Egyptian cotton. 



1528 will be named S. nanus, Sprengl. 



1530 will be named S. Numidianus, Vahl. 



1535, authority should be " Smith." 



1538/;, authority, "Koch," is a var. with compact 

 spikes and enlarged tubers on the roots. 



1539/' is a var. found by Dr. White in Perthshire,., 

 described by Sonder in his " Flora of Hamburg." 



1540 is 1387, 7th ed. 



1541 is 1388, 7th ed. 



1544, /'. longifolium, Hoppe, is a large form of 

 the plant, c. alpinum, Gaud., is the Alpine one- 



* Nature, vol. xxxiv. p. 342, 1886. 

 t Geol. Mag., p. 468, 1887. 



