376 Reviews — Prof. C. D. Walcott — Cambn'cDi Pa/ceontology. 



particulars of a highly interesting boring at Ebbsfleet near Ramsgate, 

 where Carboniferous Limestone was reached below Coal-measures 

 (103 feet thick), at a depth of 1,159 feet. 



Another article, "On Diversions of the Bourne near Chertsey," 

 is by Mr. C. N. Bromehead ; a third is on " Orthis proava''\ by 

 Dr. "E. Matley; a fourth is entitled " Kotes on the Upper Limestones 

 of the Bathgate District", Edinburgh, by Mr. M. Macgregor; and 

 a fifth is a " Note on Fossil Plants from Garallan Pit Sinking, \ mile 

 S.S.W. of Old Cumnock, Ayrshire", by Dr. E. Kidston. 



II. — Cambrian Geology and Paleontology. No. 6 : Middle 

 Cambrian Beanchiopoda, Malacostraca, Trilobita, and Mero- 

 STOMATA. By C. D. Walcott. Smithsonian Miscellaneous 

 Collections, vol. Ivii, No. 6 (publication 2051), 1912. 



SOME beautifully preserved Crustacea form the subject of the fourth 

 preliminary paper on the collections from the Burgess Shale, 

 Stephen formation, British Columbia. Altogether thirty-four new 

 species are described, ten of which belong to the Branchiopoda, and 

 represent seven new genera and four new families. Five new genera 

 of Malacostraca are instituted, and fourteen species are referred to 

 them. One new family of Trilobites — the Marrellidse — is founded 

 for the reception of four genera and six species, all new. Of the 

 Merostomata a new order is described, and thi'ee genera and four 

 species are placed in it. 



The shale in which these important specimens are preserved is 

 described as being smooth, compact, exceedingly fine-grained and 

 siliceous ; the fossils are irregularly distributed, occurring in layers, 

 and they exhibit structures that are most surprising considering their 

 age, thus indicating very little disturbance since the rock was 

 deposited. In some specimens traces of the alimentary canal can be 

 observed — in the new Trilobite genus 31arrella, for example — and in 

 one case, in Burgessia, it is seen to be large where the hepatic tubes 

 join it, and to taper to its posterior end. In this same case the 

 hepatic caeca are beautifully preserved and have the branched structure 

 even better than in recent Copepods. 



In structure the members of this fauna are not unlike recent 

 Crustaceans of the same orders : the stalked eyes, the antennules, and 

 antennse are similar, while in the thoracic appendages there are no 

 modifications that would indicate a more primitive form. Dr. Walcott 

 thinks it probable that in such of his new Branchiopod genera 

 as Opahmia and Burgessia we see ancestral forms of the recent 

 Polyartemidse and Apodidse, and that even in Cambrian times their 

 great power of reproduction and their active movements enabled them 

 to flourish "in the midst of active and powerful enemies". There 

 is a remarkable similarity of structure in the antennae, legs, and 

 branchiae of the Burgess Shale Trilobites, and those of Ordovician 

 age, and with this new material the author now agrees with 

 Burmeister and Bernard that the Trilobites are related more closely 

 to the Branchiopods. The discovery of caudal rami in Neolemis 

 corroborates Bernard's idea that the Trilobites came from the same 



