REPORT OX l'AI,.KONT( > LOGICAL COL] 



Named in honor of Mr. Henry 



Kngelma 



nu, Geoloc 



ing party. 



Locality and position. — Devoni 



an of Neil 



's Valley, 



titude 3!>° 32', longitude 11; 

 Spirifer strigosus, Meek. 



.(July. 



Shell rather under medium size, subtrignnal. or subsemieireular, eonsiderahly 

 wider than long; hinge-line equaling the greatest width, and terminating in rather 

 salient angles. Dorsal" valve convex in the middle, compressed toward the lateral 

 extremities; mesial fold narrow, prominent, and angular, especially near the front. 

 Ventral valve more convex than the other, sloping somewhat abruptly from the umbo 

 to the sides and front; mesial sinus narrow, rather deep, with sloping sides continued 

 to the beak, which is pointed and incurved; area of moderate breadth, with well-defined 

 sloping lateral margins, apparently not continued quite to the extremities of the hinge, 

 arched and inclined back over the cardinal margin; foramen triangular, higher than 

 wide. Surface of each valve ornamented "by about eighteen to twenty-four moderately 

 distinct more or less binireating plications, about six or seven of which usually occupy 

 the mesial fold, and five or six the mesial sinus. 



Length of hinge, about 1.19 inches; diameter from hinge to front, 0.63 inch; 

 height of area, 0.16 inch. 



The central plication of the ventral valve usually extends along the middle of the 

 sinus nearly or quite to the beak; while the two or three rather smaller ones in the 

 sinus on each side, in most cases, coalesce with those forming the margin of the sinus 

 before reaching the beak. Along the middle of the rather sharp fold of the dorsal 

 valve there is a groove, usually a little larger than those between the other plications, 

 and corresponding to the central plication of the opposite valve. A few of the plica- 

 tions on each side near the mesial sinus and fold sometimes bifurcate once, but the 

 others seem to be all simple. The specimens are not well enough preserved to have 

 retained fine surface-markings, if there were any. 



This shell is quite unlike all of the other forms from this region, and I know of no 

 very closely allied species from other localities. 



Locality and position. — Same as last. 



Genus ATRYPA, Dalman. 

 Atrypa reticularis (Lin.), Dalm. 



Plate 1, fig. 6, a, b. 

 Anomia reticularis, Linnseua (1767), Syst. Nat., ed. xii, vol. 1, 1152 ; and Encyc. Method., pi. 242, fig. 4, a, b, c. 



For the long list of subsequent synonyms, with references, &c, see Mr. Davidson's and other extended 

 works on Paleozoic BracMopoda. 



Of this widely-distributed species there are quite a number of specimens in the 

 collection from a locality near the south branch of Humboldt River. They are all 

 rather small, and have more the aspect of Upper Silurian than Devonian varieties. As 



