240 



THE GEOLOGIST. 



The extreme abundance of the homstone nodules in the palaeozoic lime- 

 stones of America will render it easy to our Transatlantic contemporaries 

 to multiply observations in this new field of research, which presents an 

 interesting addition to the labours of the microscopist, while English geo- 

 loo-ists should at once examine the siliceous concretions which occur in our 

 British rocks of older than cretaceous age. It will be remembered by 

 those who undertake such examinations that the use of turpentine renders 

 the chips of chert almost as transparent as glass. 



In ' Silliman's Journal' for May, Dr. White publishes descriptions with 

 figures of some of the more frequently recurring forms hitherto observed 

 by him ; some of which figures we copy here for the benefit of our readers, 

 referring those who are specially interested in the subject to our first-class 

 contemporary, the 'American Journal of Science,' for further details. 



EEYIEW. 



MonograpMe des Gasteropodes et des CepJialopodes des Couches Cretacees 

 Superieures du Limhourg. By M. Binkhorst. 



We recently noticed (page 79) an excellent Monograph by this geologist 

 on the Gasteropoda of the Upper Chalk of Limbourg ; since then we are 

 indebted to M, Binkhorst for a copy of his valuable Monograph of the 

 Cephalopoda of the same geological beds, illustrated by six handsome 

 quarto plates, containing ninety-one figures. The letter-press consists 

 entirely of descriptions, lists of synonyms, and stratigraphical ranges of 

 the following species, which are met with in that district : — Belemnitella 

 mucronata, D'Orb. ; AcantJioteuthis MaestricJitensis, n. s. ; Nautilus de- 

 joressus, n. s. ; N. Heherti, n, s. ; N. Vaelsensis, n. s. ; N. Lehardii, n. s. ; 

 N. Danicus, Schlot. ; Rhyncholithus Deheyi, Miiller ; JR. minimus, n. s. ; 

 R. ? Ruchii, Miiller ; Ammonites jpedernalis, Buch. ; A. colligatus, n. s. ; 

 A. DecJieni, n. s. ; A. exilis, n. s. ; A. 'pungens, n. s. ; A. laticlavus?, 

 Sharpe ; Ajptyclius rugosus, Sharpe ; Samites rotundus, Sowerby ? ; S. 

 cylindraceus, D'Orb. ; Scaphites constrictus, D'Orb. ; Baculites Faujasi, 

 Lamarck ; B. aiiceps, Lamarck ; B. carinatus, n. s. 



We are very glad to know that M. Binkhorst is busily preparing a 

 Monograph of the bivalves of these interesting beds of Chalk, and that 

 every day his researches are rewarded with new forms, not only of 

 Conchifera but of Gasteropods. 



Within the last few weeks he has added no less than thirty new species 

 of the latter, to the number described in his Monograph, a list of which 

 was given in our February number. 



Eii-h as tliis Maestricht Chalk is in genera and species, we are satisfied 

 that the " Chalk-rock " beds of our own Upper Cretaceous Series would 

 as richly reward English collectors as we are glad to find these Maestricht 

 beds are rewarding our indefatigable and talented Flemish contemporary. 



