Geological Society of London. 373 



The Gault yielded 16 genera and over 30 species of Foraminifera, 

 and 20 species of Entomostraca, 4 of which are new, together with 

 many young forms of Gasteropods and Cephalopods. 



But the chief interest of Mr. Moore's investigations centres in the 

 67 feet of strata intervening between the Gault and Devonian. In 

 this marly and oolitic-looking deposit he found no less than 85 

 diiferent kinds of organisms, exhibitiHg a singular admixture of 

 marine and lacustrine forms of life. Foraminifera are rare, but 

 Entomostraca and Polyzoa are very abundant. Some genera are 

 found, such as Carpenteria, Saccammina, Thecidium, and Zellania, of 

 which the range in time is greatly extended by these investigations. 



The author fully confirms Mr. Etheridge's reference of the beds in 

 question to the Neocomian period, widely as they differ in physical 

 characters from the Lower Greensand strata of the south-east of 

 England. From a careful study of the nature and condition of 

 preservation of the minute organisms, he concludes that the deposits 

 which contain them were formed at first in shallow lacustrine 

 hollows on the surface of the Devonian rocks now lying buried at 

 a depth of 1000 feet below London, and that these lakes were 

 invaded by the waters of the Neocomian sea, with the deposits of 

 which their sediments were in part mingled, and under which they 

 were finally buried. 



The Chair was then taken by Prof. Prestwich, M.A., F.E.S., Vice- 

 Pi'esident. 



3. " On PeJanechinus, a New Genus of Sea-urchin from the Coral 

 Eag." By W. Keeping, Esq., B.A., F.G.S., Professor of Geology in 

 the University College of Wales. 



In 1855 an Echinid was described by Dr. T. Wright, from very 

 fragmentary specimens, under the name of Hemicidaris corallina. 

 Since that date two very fine specimens have been obtained, both 

 from Calne, one by Mr. Keeping, sen., now in the Woodwardian 

 Museum, Cambridge, the other in Dr. Wright's Collection. These 

 show the affinities of the Echinid to be rather with the Echinothu- 

 rid83. The author regards this species as the type of a new genus, 

 which he names Pelanechimis, and characterizes as follows : — 



Test thin, circular, depressed, consisting of (1) transversely elon- 

 gated coronal plates, (2) apical plates, (3) an actinal system of im- 

 bricating plates around the mouth. Interambulacral areas narrow at 

 poles, but rapidly broadening towards the equatoi", with 6-8 rows of 

 primary tubercles ; the plates narrow, contour rounded, slightly un- 

 dulating. Ambulacral areas more uniform, equal to ^ of the greatest 

 breadth of interambulacral areas, with two rows of primary tuber- 

 cles ; poriferous zones broad, pores trigeminal in the equatorial re- 

 gion. Primary tubercles rather small, smooth, perforated, uniform 

 over both areas ; spines small, hollow. Peristome deeply notched. 

 Actinal area about f of whole test, covered with zones of large im- 

 bricating plates, with perforations and perforated tubercles. Jaics 

 large and powerful. 



This Echinid has a marked similarity of appearance to Asthenosoma 

 (^Calveria), and the author believes that it also had a flexible test. 



4. "Eemarkson SaurocephaluSf and on the Species which have 



