Correspondence — Professor J. W. Gregory. 189 



recognized. The sequence of fossils consists of (in ascending order) 

 Glyphioceras Beyrichianum, Glyphioceras reticulatum (type), 

 Glyphioceras reticulatum (certain mutations, including G. hilingue 

 (Salter)). Specimens of Glyphioceras approaching the characteristics 

 of Gastrioceras in their mode of coiling and in ornament appear in 

 abundance at horizons fairly well down in the G. reticulatum 

 mutations beds ; and near the summit of the Grit series they are 

 very much in evidence. These specimens of early Gastrioceras differ 

 considerably in their ornament from one another and form a 

 complex group. 



A study of the sutures of the above goniatites suggests that all 

 the species belong to one group of closely allied forms. The 

 crenistria-sphcericum-striaticm group, which underlies the above 

 zones and in Yorkshire characterizes the Upper Limestone Shales, 

 is apparently (as was observed by Haug) a group distinct from the 

 above. Very young sutures of crenistria closely resemble the adult 

 sutures of the reticulatum group. A specimen of sphcericum has a 

 spindle-shaped initial whorl. G. Phillipsi (F. & C.) appears to be a 

 synonym of G. striolatum (Phill.). 



CORRESPONDENCE. 



PKOFESSOR KENDALL ON ENGLLSH ESKERS. 



Sir, — Professor Kendall's article (Geol. Mag., March, pp. 98-103) 

 is based on a series of misquotations and misrepresentations and 

 complaints' as to the omission of irrelevant evidence. His 

 irresponsibility as a critic lessens my satisfaction at his agreement, 

 in the two cases with which he deals, with the essential conclusions 

 of my paper, viz. that the Lanshaw Delves is a moraine and not an 

 esker, and that the group of drifts near York are not concentric 

 kames connected by osar. 



The Lanshaw Delves belong to a double series of glacial formations 

 which Professor Kendall fails to distinguish. One is the Lanshaw 

 Delves itself, a continuous bank of sandy loam and angular 

 unglaciated blocks of Millstone Grit. The other is a series of denuded 

 mounds of ordinary glacial drift which extend for three or four 

 miles eastward of the Lanshaw Delves and contain an abundance 

 of Carboniferous Limestone. Professor Kendall misapplies the 

 latter part of a paragraph from the Geological Survey Memoir on 

 the Yorkshire Coalfield to the Lanshaw Delves. If he had included 

 the first three lines of that paragraph it would have been clear that 

 the part he quotes refers not to the Lanshaw Delves, but to some 

 drift mounds miles eastward from it. The quotation is from the end 

 of a section headed " High-level Eskers ". Its first paragraph 

 describes the Lanshaw Delves (p. 779), and the gravel mounds 

 near Ha-wksworth. The second paragraph (p. 780) refers to the 

 length and slope of the drift ridges. The third paragraph begins : 

 " Besides the above there are several isolated mounds and banks 



