108 REPORT — 1860. 



Very few of the fossils common to both the Cornbrash and Inferior Oolite are not 

 found in the intermediate formation ; and in the above list of Cornbrash fossils, a large 

 per-centage are well-known Great Oolite speuies. The great comparative rarity of 

 the Cephalopoda is also noticeable, both in the Cornbrash and Forest Marble; one 

 solitary, mutilated fragment of an ammonite in the Islip Cornbrash is the only 

 example of this class I have seen from these two formations during several years 

 active collecting. 



On the Intermittent Springs of the Chalk and Oolite of the Neighbourhood of 

 Scarborough. By Captain Woodall, M.A., F.G.S. 



On the Avicula contorta Beds and Lower Lias in the South of England. 

 By Thomas Wright, M.D., F.R.S.E. and G.S. 



The black shales, with their interstratified sandstones and bone- beds which lie at 

 the base of the Lias, have by one class of observers been grouped with the Lias, by 

 others with the Trias ; the author had made a series of observations on these beds, 

 where they are exposed at Westbury, Wainlode, and Aust, on the banks of the Severn ; 

 and at Penarth and VVatchet, on the shores of the Bristol Channel : in all these sec- 

 tions he had found several species of Conchifera, which are special to the beds, as 

 Avicula contorta, Portl., Pecten Valoniensis, Defr., Mytilus minutus, Goldf., Cardium 

 Rhceticum, Mer., Lima precursor, Querist., Ncoschizodus posterus, Quenst., Cardium, 

 sp., Cypricardia, sp., Anomya, sp., with several other small bivalve shells which he 

 was unable to determine. He found the same beds at the base of the Lias in War- 

 wickshire and Worcestershire ; and they have recently been found in Staffordshire by 

 Mr. Howell, and several years ago were discovered by General Portlock in Ireland. 

 In Germany Quenstedt calls these beds Vorlaufer des Lias; they are the true repre- 

 sentatives of the Upper St. Cassian beds of German geologists, and the Kbssener- 

 schichten of the Tyrolese. Since they were first described by Von Buch thirty 

 years ago, they have formed the subject of many interesting observations by conti- 

 nental geologists, although up to this time it has not been settled whether they belong 

 to the Trias or to the Lias. The Conchifera found in these beds in England are special 

 to them, and none of the species pass into the true Lias ; whereas it has been asserted 

 by Sir Philip Egerton and Professor Agassiz that the species of fishes found in the 

 Bone-beds of England and Ireland are Triassic forms. Should this statement hold 

 good, the evidence for the triassic character of the Avicula contorta series will greatly 

 preponderate over their liassic affinities. M. Jules Martin, in an able memoir, ' Pale- 

 ontologie Stratigraphique de l'lnfra-Lias du D£partement de la Cote-d'Or,' has exa- 

 mined these beds in the departments of Cote d'Or, Rhone, Ardeche and Isere, and has 

 placed them all as Infra-lias. The absence of the Bono-bed from the French deposits, 

 although found in Luxembourg, is remarkable; and therefore the evidence afforded 

 by the fossil fishes is excluded from M. Martin's estimate of the Palfeontological affi- 

 nities of these Infra-Liassic deposits. 



Dr. Wright divides the Lower Lias into six zones of life, each characterized by 

 certain species of mollusca which are special to it; these are — 1st, the zone of Am- 

 monites planorbis; 2nd, the zone of Ammonites Bucklandi; 3rd, the zone of Ammo- 

 nites Turneri ; 4th, the zone of Ammonites obtusus; 5th, the zone of Ammonites oxy- 

 notus; and 6th, the zone of Ammonites raricostaius. Each of these zones was sepa- 

 rately described, its fauna enumerated, and the localities where it was developed 

 pointed out. The Lower Lias in the South of England was compnred with the Lower 

 Lias of Wurtemberg, and the correlations of that formation in both countries pointed 

 out. 



