MUSEUM OF COMPARATIVE ZOOLOGY. 309 



EXPLANATION OF PLATES. 



This article is accompanied by three plates, numbered IX., X.,and XI., with fifty- 

 two figures, numbered consecutively. 



Plate IX., figs. 1-31, gives a general graphic review of the opinions held concerning 

 the relations of the trap and sandstones from 1818 to 1880. The references to the 

 originals of the drawings are given on pp. 280, 281. 



Plates X. and XI. Sketch-maps serving as guides to the localities of the observa- 

 tions above described, and figures representing some of the results obtained. Page 

 numbers refer to explanations in the text. 



Fig. 32. Turner's Falls, Mass. Fig. 33. Section of trap ridges (p. 259). Fig. 34. 

 Fragments of trap in overlying sandstone (pp. 260, 300). 



Fig. 35. About Mount Tom, Mass. (p. 261). Fig. 36. Section of Mount Tom and 

 posterior ridge (p. 261). Fig. 37. Generalized section of contact, Delany's Quarry 

 (p. 262). 



Fig. 38. Railroad cut in posterior trap ridge. West Springfield, Mass. (p. 263). 



Fig. 39. Map and section of curved trap ridge at Beckley Station, Middletown 

 Branch Railroad, Conn. (pp. 264, 265, 306). 



Fig. 40. The Hanging Hills from Meriden (p. 265). Fig. 41. The same in section 

 (p. 266). Fig. 42. Map of the same (p. 266). Fig. 43. Tlie same with Lamentation 

 Mountain, as seen from Wallingford, Conn., showing place and throw of probable 

 fault (pp. 266, 305). 



Fig. 44. Dikes near East Haven, Conn. (pp. 268, 292). 



Fig. 45. Side of ragged dike, Wallingford, Conn. (p. 266). 



Fig. 46. Base of Palisade trap cutting sandstone, Weehawken, N. J. (p. 270). 



Fig. 47. Garret Rock, First Mountain, Paterson, N. J. (pp. 273,304). Fig. 48. 

 Gorge at Passaic Falls, Paterson (pp. 272, 300). 



Fig. 49. Peculiar conglomerate overlying First Mountain trap, Feltville, N. J. 

 (p. 275). Fig. 50. a, b, the same, natural size (p. 275). 



Fig. 51. Intruded trap sheets, Martin's Dock, below New Brimswick, N. J. 

 (pp. 276, 295). 



Fig. 52. Intruded trap sheets, near Point Pleasant Station, Belvidere Railroad, 

 N. J. (pp. 277, 295). 



