Reuieius — The Geology of Tvybridge and Modbury. 217 



to our knowledge of Antarctic fossil floras that lias yet been published. 

 It is true that Hope Bay, Graham Land (lat. 63° 15' S.), lies Avithout 

 the Antarctic circle, but, as the author justly points out, the present 

 climate of this region is purely Antarctic and its known flora includes 

 only two species of the higher plants. 



It is very remarkable to find that of the specimens from Graham 

 Land, collected by members of the Swedish South Polar Expedition 

 (which are not only far more numerous but much better preserved 

 than those obtained in the Antarctic region either before or since), 

 not a few are the same species as those with which we have long 

 been familiar in the Lower Oolites of the Yorkshire coast. No less 

 than nine of the species, including Todites WilUamsoni (Brongn.), 

 Cladophlehis denticulata (Brongn.), and Coniopteris hymenophylloides 

 (Brougn.), are British plants, and a very large proportion of the genera 

 are also found in England. Surely current opinion with regard to the 

 worldwide distribution of Mesophytic vegetation could receive no 

 more striking confirmation than is to be found in Dr. Halle's memoir. 



The author distinguishes sixty-one Jurassic types either generically 

 or specifically, and full and clear descriptions are given of each. Of 

 these, twenty-one are new species, and two {Elatocladus and Schizo- 

 lepidella) are new genera. The systematic portion of the work is 

 followed by a discussion, at considerable length, on the known 

 geographic distribution of the plants and the age of the beds, which 

 are regarded as Middle Jurassic. 



Dr. Halle may be congratulated on the results of his labours, and 

 our thanks are due to him for the care and research which he has 

 obviously bestowed on the preparation of this memoir. It is no 

 doubt true that the study of fossil plants demands, perhaps more 

 than any other subject, an accurately balanced judgment. Dr. Halle 

 has shown, by the way he meets the difficulties presented by this 

 material, that he is possessed of such judgment in a high degree. 

 Many of the suggestions which he makes with regard to difficulties 

 arising from homoplasy and synonymy are worthy of careful attention 

 at the hands of all those who are working in the same field. We 

 mory also congratulate Professor jS^athorst on the achievement of his 

 pupil, whom he has obviously inspired Avith something of his own 

 enthusiasm, care, and discrimination. 



In conclusion, a word of praise may be added with regard to the 

 clearness and general excellence of the plates (eight double and one 

 single) which accompany and illustrate the memoir. "p a N A 



II. — Geoiogicax Survey Memoir. 

 The Geology of the Country around Ivybridge and Modbury. 

 By "W. A. E. UssHEE, F.G.S., with chapter on Altered Rocks by. 

 G. Barrow, E.G.S. 8vo ; pp. vi, 137, with 6 plates and 26 text- 

 illustrations. Printed for His Majesty's Stationery Office, 1912. 

 Price 3s. 

 rilHIS is an explanation of the colour-printed Geological Survey 

 _L map, Sheet 349. It takes in the eastern part of Plymouth, and 

 adjoins Sheet 348, which was described by Mr. Ussher in " The 



