Coffin's Winds of the Globe. 273 



limestone. Beneath this latter, at about a line's depth, was 

 shown a portion of the plate in question. At present the 

 specimen consists of three parts, or rather four : (1) The inner 

 surface of the glabella ; (2) a limestone cast of the same ; (3) 

 the epistoma attached to the lower side of No. 2; (4) a cast 

 of the lower or mouthward side of the epistoma, and preserv- 

 ing its spine. The layer holding the epistoma came away in 

 several pieces. These have been glued together, and the rela- 

 tions of the parts of all four of the pieces can be made out with 

 ease and certainty. 



As will be seen from the figure, the plate is in a fragmentary 

 condition. Compared with the hypostoma it is probably 

 represented in an inverted position in the drawing. The 

 upper portion in the figure is probably the backward portion 

 in the specimen. This is, moreover, its position beneath the 

 glabella. It lies diagonally across the latter, with its spinous 

 portion resting directly beneath the neck-segment It has 

 doubtless become detached and slipped backward. It appears 

 to me probable that the straight dotted line in the figure indicates 

 approximately the middle line of the perfect specimen. This 

 is all that I desire to say upon the subject at present. 



To sum up : I believe the facts which have been presented 

 prove conclusively that we have in Olenellus asaphoides an ex- 

 ample of the metamorphoses of trilobites, and clear up some 

 points that have always been in doubt concerning the genus, 

 besides affording us a more complete life-history than we have 

 hitherto possessed of any trilobite from American strata In my 

 investigation of this singular life-history I have striven earnestly 

 to read the record aright. How far I have succeeded m this must 

 remain for my fellow laborers in the department to determine. 



All of the specimens described and figured m this paper 

 were collected by the writer from the limestone beds of the 

 Lower Potsdam Group at Troy, K Y. 

 New York, February, 1877. 



ART. XXXI.-The Winds of the Globe; or the laws of Atmos- 

 pheric Circulation over the surface of the Earth; by James H 

 Coffin, LL.D., Professor of Mathematics and Astronomy m 

 Lafayette College * 

 This volume, to which the author devoted many years of 



earnest labor, may be considered, as its title implies, an ^ exte ^ 

 * The Winds of the Globe; or the Laws of 



of the Earth; by James H. Coffin, LL.D., 



