GASTROPODA. 953 
Raphistomida.] 
?Scatires, Emmons. Shell turbinate, spire only moderately high; whorls flat 
above rising step-like one above the other, sharply angular at the periphery, 
produced below; no umbilicus; aperture subtriangular, apparently drawn out below; 
columellar lip rather thick, slightly twisted. Surface markings and form of outer 
lip unknown; probably as in Omospira and Raphistoma. Type, S. angulatus Kmmons. 
Fie. 4.—Scalites angulatus Emmons, Chazy limestone, Chazy, New York. View of a weathered 
specimen, imbedded in stone, showing part of the upper whorls in section and the umbilical region and 
slightly twisted columellar lip. Received from Prof. H. M. Seeley and now in the collection of E. O. 
Ulrich. 
The accompanying figure shows nearly all we could learn of this genus and 
species. The general form reminds one of certain species of Lophospira, but we are 
certain that the angular periphery of the whorls does not carry a band as in that 
genus. Unfortunately, neither the original types nor, so far as known, any of the 
specimens discovered since, afford any positive knowledge concerning the form of 
the outer lip and surface markings. Although we believe that these characters will 
prove to be essentially as in the preceding genera of this family, we must admit that 
the question is complicated by the marked resemblance which S. angulatus bears to 
Holopea supraplana. For the present then the name Scalites should be restricted to 
the species to which it was originally applied. 
Of these five genera Huomphalopterus is the most recent, being perhaps entirely 
an Upper Silurian type. The others with a few doubtful exceptions, are confined 
to Lower Silurian deposits. Raphistoma begins with several species in the Chazy 
and continues to the top of the Cincinnati period; Raphistomina is known in the 
Trenton, Black River and Calciferous formations, and we have reason to believe 
that the type reaches as far back as the Cambrian; while Omospira comprises Black 
River and Trenton species and perhaps a single Upper Silurian form. Haphistomina 
strikes us as the most primitive of the four Lower Silurian types and we feel 
reasonably satisfied that the others were evolved from it. Raphistoma was produced 
by flattening the spire, and by the anterior prolongation of the central portion of 
the lower lip, the latter modification causing the hook of Raphistomina to be replaced 
by a notch in the upper side of the outer angle of the aperture. Huomphalopterus 
differs chiefly in its more rounded volutions, and excessively developed carina. The 
