. Bulletin - New York State Museum. Science. BEEKMANTOWN AND CHAZY FORMATIONS OF CHAM PLAIN BASIN 497 the section slightly compressed oval with very little difference be- tween the minor and major diameters (14 and 15 mm in one speci- men) ; the ventral side being a little narrower than the dorsal. The largest diameter observed is about 40 mm at the base of the living chamber; the curvature is strong, an arc of 35 mm having a hight of 4 mm. Only the base of the living chamber has been observed and the apical part of the conch is missing. The cameras are very shallow, there being 4 of them in t
. Bulletin - New York State Museum. Science. BEEKMANTOWN AND CHAZY FORMATIONS OF CHAM PLAIN BASIN 497 the section slightly compressed oval with very little difference be- tween the minor and major diameters (14 and 15 mm in one speci- men) ; the ventral side being a little narrower than the dorsal. The largest diameter observed is about 40 mm at the base of the living chamber; the curvature is strong, an arc of 35 mm having a hight of 4 mm. Only the base of the living chamber has been observed and the apical part of the conch is missing. The cameras are very shallow, there being 4 of them in the space of 10 mm; they are curved, strongly arching forward on the convex (ventral ?) side; the sutures nearly straight transverse with a broad lobe on the convex side; the septa flat (their depth is about i^ that of the cameras) and bend- ing orad on the ventral side. The siphuncle is large, strongly nummuloidal, ^i?si Ooceras t^ o' o-' 'seelyisp, nov. expanding to twice its width (one eighth the width uon" Naturalsfze of the shell) in the cameras. Septal neck only present on dorsal side; the interseptal segments, which are of disk- like shape, marginal in position on the convex side of the conch. Position and localities. In the dove-colored limestone (Chazy Ci) of Isle La Motte, and of the outcrops north of the road to Little Monty bay south of Chazy village. One specimen was col- lected by Professor Hudson in the lower Chazy of the neighbor- hood of the normal school at Plattsburg N. Y., where it is asso- cited with Rhynchonella acuticostris, Scalites angulatus^ Harpes antiquatus, etc. Observations. The most striking characters of this species, which is a typical Ooceras, are found in the structure of the si- phuncle and the section of the conch. In the siphuncle the septal necks are absent on the ventral (outer) side [see fig. u], but strongly developed on the dorsal side where they are bent outward and hooklike in section. This is one of the diagnostic features of th
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectscience, bookyear1887
