142 Reports and Proceedings — Geological Society of London. 



(" Genesis of the Arietidae "), Branco regarded the cicatrix-bearing 

 conical end of the shell in Orthoceras as the embryonal shell or 

 protoconch ('' Anfangskammer "), but Hyatt, observing a wrinkled, 

 wart-like lump at the apex of the St. Cassian specimens, came to 

 the conclusion that this was the true protoconch, and assumed from 

 its shrunken condition that it was originally composed of conchiolin 

 and hence easily destructible. The specimen (see Figure) which 

 is the subject of Mr. Clarke's very interesting communication was 

 found in the Styliola limestone of the Genesee shales, on Ganandaigua 

 Lake, New York State, in an association of species which represents 

 the earliest appearance in North America of the [Upper Devonian] 

 fauna of Goniatites (Gephyroceras) intumescens, Beyrich. The speci- 

 men " consists of the first or apical chamber of the shell, to which 

 the protoconch is attached. The upper end of the specimen shows 

 the first septum .... to be circular and with a central sipho. The 

 lateral walls of the first chamber taper rapidly to the plane of con- 

 junction with the protoconch, and its depth is about one-half that 

 of the latter. The protoconch itself is semi-ovoid in shape, and 



a. Outline of the first chamber of an Orthoceras with protoconch attached ; 

 b, base of the first chamber [a) showing siphuncle. Greatly enlarged. 



when compai'ed with those of Orthoceras previously described or 

 figured [in the shrunken condition] is of very large size. It shows 

 no indication of shrinking or other irregularity and its distal ex- 

 tremity is perfectly smooth. The length of the entire specimen is 

 •85 mm. ; that of the protoconch, "60 mm. ; and the diameter of the 

 first septum, 1 mm." Mr. Clarke observes in the concluding part 

 of his paper that *'it is probable that this protoconch has been 

 derived from a shell so young that atrophy and wrinkling have 

 not manifested themselves, as they may have done with the more 

 mature development of the shell. This, I believe, is the only 

 recorded observation of the protoconch in Palaeozoic forms of 

 Orthoceras, and its shrunken condition in the post-Paleozoic forms 

 may have a phyletic significance." Arthur H. Foord. 



I^,E:FOI^TS j^istid zPE-oosiEiDiniTa-s. 



Geological Society of London. 



L— January 24th, 1894.— W. H. Hudleston, Esq., M.A., F.R.S., 

 President, in the Chair. The following communications were read : 



1. "The Ossiferous Fissures in the Valley of the Shode, near 

 Ightham, Kent." By W. J. Lewis Abbott, Esq., F.G.S. 



The fissures occur in a promontory of Kentish Rag between two 

 tributaries of the Shode. There are four fissures in this promontory, 

 striking at right angles to the valley. Details of the physiography 



