SEELET — Oil CHALK GASTEEOPODS. 



89 



Fig. 19. Cristellaria Italic®, Defrance (D'Orbigny's Modeles,* 

 nos. 19 and 85). This is not an uncommon form where Cristel- 

 larise abound, either in the recent or the fossil state. 



Besides the foregoing, we have seen Trochammina incerta, D'Orb., 

 among the specimens from the Hampstead well, in Mr. Wetherell's 

 collection. 



The London Clay from Wimbledon Common was got at about 100 

 feet in a well-boring. That from Chelsea came from the foundations 

 of the Battersea Park Bridge. 



The Foraminifera of the London Clay indicate a depth of about 

 100 fathoms for the sea, in which it was deposited in this district. 



The accompanying Table shows the Foraminifera that we have re- 

 cognized in the London Clay, arranged according to the classification 

 proposed by Dr. Carpenter in his ' Introduction to the Study of 

 Foraminifera,' 1862. The asterisk indicates their presence merely 

 (the relative abundance not being known) ; their frequency and con- 

 dition are shown in some of the columns by the following letters : — 

 re. rather common ; c. common ; rr. rather rare ; r. rare ; vr. very 

 rare; vs. very small; s. small; rs. rather small; m. middle-sized ; rl. 

 rather large ; I. large. In some instances two very closely related, 

 but still notable, varieties are mentioned together. 



CUTTINGS FBOM A NOTE-BOOK ON CHALK 

 GASTEBOPODS. 



By Haruy See let, F.G.S. 



Two years ago, collecting matter for future use, in travelling over 

 the Chalk-lands, I made, in the museums visited, such brief memo- 

 randa of striking fossils as might save the trouble of comparison with 

 other specimens. The notes were never intended for publication in 

 their present form, but as any more extended work on the subject is 

 at present impossible, such of them as I have permission to print 

 may be found useful to others engaged on similar work. 



This series is part of the magnificent collection in the Brighton 

 Museum ; to the Committee of which I am indebted for the oppor- 

 tunity of making use of them. 



Ceritiiium ornatissimum, var. 



Conical, twice as high as wide. Many-whoiied ; whorls flat and narrow, being four 

 times as wide as high. Each whorl is ornamented on the upper and lower sutural 

 margins by a very numerous row of closely-placed tubercles. The anterior row has the 

 tubercles elongated longitudinally ; those of the posterior row are more bead-like. Con- 

 necting these rows are half as many again narrow, sharp, upright ribs. The tubercles 



* A set of these can be seen in the British Museum. 

 YOL. YII. N 



