MOOEE ABXOKMAL SECO:JfDAEY DEPOSITS. 475 



ft. in. 



(Grey sand with Spirifer Walcottii, Gryphea 

 incurva, &c.,Belemnites clavatus, B.acutus, 

 &c 6 



Rhsetic 

 White Lias. 



I Various beds as at Camerton, &c 10 



At this place there is the interesting phenomenon of only three beds, 

 18 inches in thickness, occurring between the Ehgetic and Middle- 

 Lias formations, and representing the great thickness of interposed 

 beds elsewhere. As the thick-bedded marlstone, in every other sec- 

 tion near, immediately succeeds the stone with Ammonites raricos- 

 tatus, I am rather uncertain whether to classify the upper grey sand- 

 bed with the Middle or the Lower Lias, or whether, from its having 

 organic remains in common with both, it should not be regarded as 

 a passage-bed. It is one of much palgeontological interest, from the 

 fact of my recognizing in it the genus Le-ptcena, and thus linking this 

 Palaeozoic genus in this county with the five species I have abeady 

 discovered in the Upper Lias of Ilminster. My esteemed friend 

 Dr. Deslongchamps, of Caen, whose valuable memoirs have added 

 so much to our knowledge of the Secondary rocks of the south of 

 France, has akeady discovered this species at Fontaine-etoupe-Four, 

 in Normandy, and has described it under the name of Leiotceaa 

 rostrata. It is stated by that author that it occurs exclusively in 

 the Argiope-bed of that locality ; but although, when I describe the 

 Whatley section, it will be found in this association there, such is 

 not, as far as my knowledge goes, the case at Munger. I behove that 

 M. Deslongchamps's specimens have been collected from fossiliferous 

 pockets of Liassic age redeposited on Silurian rocks ; and if so, their 

 geological horizon can be better fixed at Munger. Of the Belemnites 

 associated with them, B. clavatus has been found in the Middle Lias, 

 but B. acutus has hitherto been regarded as a Lower-Lias species. 

 The four" genera of Foraminifera given below are Middle-Lias forms ; 

 but these organisms are known to have a very wide range. The 

 Starfishes are represented by a beautiful little Tro'pidaster jjectina- 

 tus, Forbes, with its rays perfect, and only about a line in breadth. 



The two lower beds undoubtedly belong to the Lower Lias ; and if 

 the upper is not considered to belong to this group, the horizon of 

 Leptmia rostrata must be fixed at the base of the Middle Lias. As 

 in France, it is accompanied by L. BouchardU, hitherto found only in 

 the Upper-Lias Leptaena- clays of Ilminster. The Munger beds are 

 in great part composed of the disjointed ossicles of Pentacrinites. 



List of Oi^ganic Remaitis from Munger. 



Cristellaria rotula, Lam. 



lituus. 



Lingulina tenera, Born. 



Nodosaria Zippei, Bom. 



Cidaris. 



Ophioderma (joints). 



Peutacrinus. 



Tropidaster pectinatus, Forbes. 



Serpula. 



Crustacea, claws of. 

 Entomostraca. 

 Discina (fragments). 

 Leptsena Bouchardii, Dav. 



rostrata, Desl. 



Rhynchonella furcillata. 

 Spirifera verrucosa (S. rostrata ?). 



