CHAZY LIMESTONE. 27 



marble of lie la Motte and other localities it is quite abundant, and the polished slabs 

 often present beautiful sections of this shell. This marble, being used for hearthstones, 

 doorsteps, doorsills, etc., is extensively distributed by commerce, and meets one at great 

 distances from its locality, always recognizable by this fossil. Indeed, some of the doorsills 

 ■of the Astor House in New- York, and of many of our public buildings, present good 

 examples of the fossil.* Its geographical range is known to be very great, extending from 

 Northeastern New- York to Virginia, and even into Kentucky and Tennessee, and north- 

 westerly nearly to Lake Superior. 



Localities. Chazy, Clinton county ; Watertown, Jefferson county ; He la Motte ; Win- 

 chester, Virginia ; St. Joseph's Island, in St. Mary's River. {State CoUectton ) 



47. 1. SCALITES ANGULATUS. 



Pl. VI. Figs. 1 a, b. 

 Sealita angiUatta. Conk ad in MS. Emmons, Geol. Report, pag. '312, fig. 1. 



Subfusiform, ventricose in the middle ; spire conical, consisting of about four angulated 

 volutions, which, when entire, form about half the length of the shell ; suture canaliculated ; 

 aperture triangular, straight above, and terminating apparently in a short canal anteriorly; 

 canal directed forward ; columella plain ; outer lip extending from tlie body of the shell, 

 nearly rectangular to the longitudinal axis, and turning at an abrupt angle forwards, 

 slightly depressed at the angle and thickened in the centre ; upper side of the whorls 

 marked by striae directed obliquely backward, and which, on passing over the angle, are 

 directed somewhat spirally forwards. 



This remarkable shell is confined to a small extent in thickness, but is not rare in certain 

 layers at Chazy. Its peculiar form at once distinguishes it, not only from any fossil in the 

 lower strata, but from any in the whole range of the palaeozoic rocks yet known to me. 

 The lower part of the shell, only, bears some remote analogy with Bttccinum fusiforme 

 (McRCHisoN, Silurian System, pag. 642, pi. 20, fig. 19 )- 



Position and locality. In the grey lower portion of the limestone at Chazy, Clinton county. 



{State Collection.) 



• It may be well to call the attention of the geological student to this fact. The surface of the stone presents 

 hundreds of specimens worn down in this manner, some from the upper and some from the under side, which, if no 

 regard be had to the circumstance, may be considered as distinct species, the one a sinistrorsal and the other a dextral 

 shell. In the pretent instance, if the fossil be supposed to be worn down from above, the aperture is on the right side, 

 difTering from fig. 1 d. Both the horizontal and vertical sections of the shell show conclusively that it is unilocular, 

 though it has been erroneously regarded as multilocular. 



From the wide geographical distribution and limited geological range of this shell, I regard it as of great importance 

 in the identification of strata. In the contorted and partially altered limestones of Eastern New- York and Vermont, 

 where nearly all other remains are obliterated, I have found the various sections of this shell, often compressed or 

 distorted, but frequently and almost always sufficiently clear to identify the mass. 



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