80 Rerieics — D>\ Fn'fsch's Permian Amphibia of Bohemia. 



which succeed it at Eycott Hill. Analj'ses of the Litter, quoted by- 

 Mr. Ward in the paper mentioned above, show the ssilica percentages 

 of three of them to be respectively 53'3, 52-6 and 51-1. The Falcon 

 Crag rocks are shovi^n by Mr. Ward (though he coined for them the 

 unhappy term felsidolerite) to be in reality andesites, which micro- 

 scopically and chemically ' present only such differences from the 

 modern representatives of that group as we should naturally expect 

 in rocks of such great antiquity. By the kindness of Prof. A. W. 

 Williamson, the silica percentage of the red variety of the Eycott 

 Hill rock has been determined for me by Mr. T. Cooksey in the 

 laboratory of University College. He finds it to be 53-06 (one 

 determination giving 53-40 another 52-73)* with a specific gravity of 

 2-754. The rock must therefore remain among the basalts (the 

 glassy condition of its base renders the name dolerite inappropriate). 

 It belongs, however, to the side of the basalt group which is the 

 richer in silica, and is' nearly represented among modern rocks by 

 some of the basalts of the Inner Hebrides in Prof. Judd's collection. 

 It also resembles in certain respects soiiie of the magma basalts 

 described b}' Boricky [PetrograpMsche Studien an den Basaltgesteinen 

 Bohmens). The amount of alteration may justify us in naming it 

 now an enstatite-diabase, but I feel no doubt that it was originally 

 a true basalt rich in glass, containing a variety of enstatite. 



la E "V" I IB "W S. 



Dr. Fkitsch's Permian Amphibians of Bohemia. 



^E. ANTON FPiITSCH has now made such progress with his 

 Monograph on the Fauna of the Bohemian Permian rocks 

 that we are able to recognize it as one of the most important and 

 one of the ablest of modern contributions to Palasontology. For 

 excellence of description it has not been surpassed ; while from the 

 minute dimensions of most of the Amphibian remains, care has been 

 required in deciphering osteological characters, which has resulted in 

 a perfection of osteological labour. Specimens ofi'ering fewer diffi- 

 culties might not perhaps have been studied with the same complete- 

 ness. Professor Fritsch has shown that he is a learned comparative 

 anatomist, whose wealth of knowledge has enabled him to enrich 

 his pages with the fruits of many and varied studies, and to success- 

 fully interpret remains which are often obscure. 



The third part of the work contains descriptions of Urocordylus 

 scalaris, Keraterpeton crassuni, Limnerpeton modesium, L. laticeps, 

 L. macrolepis, L. elegans, L. obhisatum L. duhium, L. diffijcile, and a 

 note on X. caducum. Like the foregoing part it consists of 32 quarto 

 pages of text, well illustrated by many excellent figures printed with 

 the text ; and by 1 2 coloured plates. 



The memoir begins with some account of the family Nectridea, 



^ Two analyses of lavas from the Keswick disti'ict given in the Survey Memoir 

 give silica percentages of 60-718 and 59-511 respectively. 



^ He also writes, " The rock contains a small amount of calcium, less magnesium, 

 but mainly iron, aluminium and silica." 



