Reviews — Hitchcock's Geology of New Hampshire. 517 



loBvicosta, Terebratula sub- Wilsoni, Chonetes sarcinulata, Tentacalites 

 Velaini, and a few Polyzoa. 



The Crinoidal remains that M. CEhlert has been so fortunate as 

 to discover in these beds are, he thinks, sufficiently complete to 

 establish the existence of two new genera, each represented by a 

 single species. 



For these our author proposes the respective names of Thylaco- 

 crinus Vannioti and Clonocrinus Bigsbyi. 



The genus Thylacocrinus comes nearest in its formulas to Rodo- 

 crinus, Miller, and Eucrinus, Angelin ; whilst Clonocrinus, we are 

 told, greatly resembles Angelin's figure of Melocrinus spectabilis. 



This last-named species M. GEhlert is inclined to consider has 

 been erroneously referred by Angelin to the genus Helocrinus as 

 founded by Goldfuss, and he ventures to suggest that it might, 

 perhaps, be more properly classed as another species of this new 

 genus, Clonocrinus. (The Plates are not given.) B. B. W. 



REVIEWS. 



I. — The Geology op New Hampshire. By 0. H. Hitchcock, 

 State Geologist, and Assistants. Vol. II., Part 2, Stratigraphical 

 Geology ; Vol. III., Part 3, Surface Geology ; Part 4, Mineralogy 

 and Lithology ; Part 5, Economic Geology. Accompanied by a 

 Folio Atlas of Maps and Illustrations. (Concord, 1877-78.) 



THESE two volumes, published in 1877-78, conclude the report 

 on the Geology of New Hampshire, and give the results of the 

 exploration of that State, under the direction of Mr. C. H. Hitchcock. 

 Filling more than 1,200 pages, they contain a detailed account of the 

 geology of the different districts of the State, preceded by a brief 

 notice of the relations of the geology of New Hampshire to that of 

 the adjacent territory. The second volume, on the Stratigraphical 

 Geology, is mostly due to the labours of Mr. Hitchcock, chapters ii. 

 and v. and parts 3 and 4 being supplied by his assistant, Mr. Hunt- 

 ington. There are no formations in the State of later date than the 

 Lower Helderberg, save the surface deposits. The stratified groups 

 comprise in descending order — 1. The Cenozoic, — include the glacial 

 and modified drifts, about 450 feet. 2. Palaeozoic, — Lower Helder- 

 berg, Coos group and Cambrian Slates, 15,800 feet. 3. Strata doubt- 

 fully referred to the Palasozoic, 11,600 feet. 4. Eozoic, comprising, 

 Upper Huronian, 12,129 feet, Labrador system, Montalban, 11,370 

 feet, Lauren tian, 34,900 feet. 



The Labrador system is in very limited amount, and recent investi- 

 gations make it difficult to say that the Labrador rocks are not of 

 eruptive character, and whether (as at Waterville) they really 

 represent the Labrador system of Canada. With regard to the 

 Montalban rocks, Mr. Hitchcock differs from Dr. Sterry Hunt as to 

 their position, and from the observations of the former we are led to 

 the view that they underlie and not overlie the Huronian, though the 

 precise relationship is not beyond controversy (p. 669). The eruptive 



