GUELPH FAUNA IN THE STATE OF NEW YORK 65 



While a few examples show the same ratio of spire to body whorl 

 (2 : 3) as that given by Whiteaves, many of the specimens from Rochester 

 have a decidedly more elevated spire, which sometimes nearly equals in 

 hight the diameter of the body whorl. The surface sculpture oscillates 

 between the entire development of the revolving ridges and the suppres- 

 sion of the transverse ridges, and the reverse, but mostly consists of quite 

 regular, coarse, sinuous and squamose transverse ridges. 



Dimensions. An average well preserved shell has a hight of 30 mm 

 and a basal diameter of 39 mm. 



Observations. There is no likelihood of confounding this with any 

 other described form. The general type of surface is of the same plan as 

 that of P. scamnata, but the sparseness of the revolving ridges and the 

 greater prominence of the concentric markings are pronounced. The 

 species is clearly of the same generic character as P. scamnata, but here 

 we fail to observe on any specimen evidence of the detachment of the 

 body whorl at the aperture. 



coelidium nom. nov. 



Coelidium macrospira Hall (sp.) 



Plate 7, fig. 2-8 ; Plate 10, fig. 13 



Murchisonia macrospira Hall, Paleontology of New York. 1852. 2:346, 



pl- 83, ng- 5 

 Murchisonia loganii Hall, Paleontology of New York. 1852. 2:346, pl. 84, 



fig. 4a, 4b 

 Murchisonia macrospira Billings in Logan's, Geology of Canada. 1863. 



P- 339, fi g- 334 

 Murchisonia macrospira Nicholson, Paleontology Prov. of Ontario. 1875. 



p. 70, pl. 3, fig. 9 

 Murchisonia macrospira Whiteaves, Paleozoic Fossils. 1884. v. 3, pt 1, 



p. 27, pi. 4, fig. 7, 7a 

 Murchisonia logani Whiteaves, Paleozoic Fossils. 1 895. v. 3, pt 2, p. 80 

 Murchisonia macrospira Whiteaves, Paleozoic Fossils. 1895. v. 3, pt 2, 

 p. 81 

 In describing the fossils which he had collected from Gait and vicinity, 

 Professor Hall applied the name Murchisonia loganii to a turriti- 



