] ir, PALJEONTOLOGY OF NEW YORK. 



lobes by a low, narrow furrow. The baso-lateral furrows cut off two pyriform 

 lobes, isolated by deep sulci on all sides. In front of these lobes the margin 

 of the glabella shows two faint lateral indentations which are more con- 

 spicuous on the casts of the internal surface. 



The surface of the cephalon is ornamented by a few faint, sometimes fine 

 and crowded pustules upon the glabella, a single strong tubercle on each of 

 the basal lobes, numerous sharp tubercles on the frontal area, and close upon 

 the frontal edge sixteen to eighteen head-like tubercles arranged in a single 

 row about the border. A single example has the frontal area strongly pit- 

 ted, a feature which gives it a similarity to Phai'-thonides varicella, of the Upper 

 Helderberg group. 



Dimensions. Length 4 mm., width 4 mm. 



Observations. The specimen figured in the Illustrations of Devonian Fossils 

 (lac. cit.) is a fragment from the crystalline layers of the Hamilton group, at 

 Eighteen-mile Creek, Erie county. As the species was described in the ex- 

 planatory text accompanying the plate upon which the figure is given, under 

 the name Pkillipsia? ornata, and it being subsequently ascertained that this 

 specific term was preoccupied by Portlock for a species of Phillipsia, Mr. S. A. 

 Miller changed the specific name to coronata (Catalogue of American Palaeozoic 

 Fossils, p. 221). Since, however, the fossil proves to be a Cyphaspis, its 

 original specific designation may be restored, especially as Cyphaspis coronata is 

 a name already used by M. Barrande. 



Examples of this species are not uncommon in the limestones at the base of 

 the Hamilton shales, in Ontario county, and in association with them is a 

 varietal form which may be designated : 



Cyphaspis ornata, var. baccata, n. var. 



PLATE XXIV. FIGS. 22,23. 



This form differs from the type of the species in the following particulars, 

 viz.: greater size (average dimensions, length 6 mm., width 5 mm.); frontal 

 area bearing a few pustules near the glabella, but thence forward smooth and 

 sometimes minutely pitted; tubercles on the margin fewer and larger; the 



