58 Prof. J. Van der Hoeven on the Anatomy 



the Upper Lias in Gloucestershire, which, according to Mr. Hull 

 of the Geological Survey, amounts at least to 200 feet in many 

 parts of the Cotteswolds. 



These strata, as well as those of the Inferior Oolite, are per- 

 fectly horizontal. When the Railway was in progress, the top 

 beds of the Lower Lias just below the Marlstone were exposed 

 at Kilsby, and were as usual very rich in fossils, similar for the 

 most part to those found in the equivalent strata at Campden, 

 and Hewlett^s Hill near Cheltenham. 



The summit of Edge Hill in Warwickshire is capped by the 

 Marlstone, the Upper Lias having been denuded; but small 

 boulders of the ' fish bed,^ containing scales of fish and ' Inoce- 

 ramiis dubiiis/ are of frequent occurrence in the vale below, 

 showing that it formerly occupied its normal position above the 

 Marlstone in that district. 



At Alderton, in Gloucestershire, the following strata were ex- 

 posed below the ' fish bed ' in April 1856, which seemed to be 

 richer in fossils than usual, and therefore I have noted them 

 here, which will enable the reader to compare them with those 

 at Bugbrook above mentioned. 



Brown and dark shales with many Ammonites, Inoceramus 

 dubius, Rostellaria (abundant), Cidaris^, Nucula, Avicula, and 

 Aptychus. These are succeeded by two or three blue marly 

 bands divided by shale, which contain a univalve like a Ceri- 

 thium, Avicula, Nucula, Pholadomya, Pecten, Astarte, and Am- 

 monites. A light blue, slightly indurated marl reposes imme- 

 diately upon the Marlstone. The total thickness of these clays 

 and marl.s forming the base of the Upper Lias is about 30 feet. 



VIIL — Contributions to the knowledge of the Anatomy of l^auiilvis 

 Pompilius, L., especially with reference to the male animal. 

 By J. Van der Hoeven, M.D., &c. &c.. Professor of Zoology 

 in the University of Ley den f. 



[With two Plates.] 



The Cephalopod MoUusks belong to those animals in which the 

 sexes are distinct. Long ago the anatomical investigations of 

 Swammerdam, Monro, Cuvier and others made us acquainted 



* A similar small species of Cidaris ( C. minuta) occurs abundantly with 

 spines attached in the Upper Lias shale at Gretton near Winchcomb, where 

 a fine specimen of a Lepidotus was lately discovered in the ' fish bed,' and 

 is now in the collection of my friend Dr. Wright. 



t From the Transactions of the Dutch Royal Academy of Sciences, 

 1856. Translated by Wm. Clark, M.D., F.R.S., Professor of Anatomy in 

 the University of Cambridge. 



