158 Bllliograplucal Notices. 



Division IIoplocartda. — Carapace leaving at least four of 

 the thoracic somites distinct. Two movable segments are 

 separated from the anterior part of the head, bearing respec- 

 tively the pedunculate eyes and the antennules. Antennal 

 peduncle of two segments. Mandibles without lacinia mobilis. 

 Posterior thoracic limbs with protopodite of three segments. 

 (The relation of the segments of the anterior thoracic limbs 

 to those of the limbs in the other divisions is doubtful.) 

 An appendix interna on pleopods. Hepatic cfeca much 

 ramified. Heart much elongated, extending through abdo- 

 minal and thoracic regions. Spermatozoa spherical. Deve- 

 lopment with metamorphosis. No free-swimming nauplius- 

 stage. 



BIBLIOGRAPHICAL NOTICES. 



Memoirs of the Geological Survey of the United Kingdom. — The 

 Cretaceous Rocks of Britain. Vol. II. The Lower and Middle 

 Chalk of England. By A. J. Jukes-Browne, B.A., F.O.S. With 

 Contributions by William Hill, F.G.S. Svo. Pages xiii and 

 568. With 93 Illustrations, including one Geological Map, two 

 Plates from photographs, and four from micrographs. E. Stan- 

 ford, London ; J. Menzies, Edinburgh ; and Hodges & Co., 

 Dublin. 1903. 



In the first volume of this series A. J. Jukes-Browne and W. Hill, 

 with others, described the Gault and Upper Greeusand of England. 

 This second volume, by the same authors, together with many 

 contributors, deals with the Lower and Middle Chalk. The thiid 

 volume will include the description of the Upper Chalk, with 

 chapters on the economics of the soil, stone, &c, on the water- 

 supply, and the physical features of chalk districts, also a complete 

 catalogue of the fossils found in all the different divisions of the 

 Chalk. The present volume begins with a general and chrono- 

 logical account of the researches that led to the definition of the 

 several stratal divisions of the Chalk ; and in the sequel the zones 

 or horizons marked out by the occurrence of particular fossils are 

 carefully explained. This part of the book seems to have been 

 written before the valuable results of the researches by Rowe and 

 Sherborn were published ; these and their subsequent work along 

 the cliff-sections of the Chalk will have greatly helped geologists in 

 the study of the strata and zones, and are largely utilized in the 

 chapters on the Middle Chalk. 



The Lower Chalk (" Ceaomaaian " in part) includes all the beds 



