140 PALAEONTOLOGY OF NEW YORK. 



lobe; thus making ten of these projecting points to the whole of the free 

 posterior and lateral margins. The surface shows a finely granular appear- 

 ance under a magnifier." 



This pygidium is different in many respects from the others here referred to 

 the genus Phaethonides, and is more nearly similar to the forms which it was 

 the evidenl intention of M. Barrande to include under the term Phaeton. The 

 glabella found in association with the pygidium, if correctly referred to the 

 same species, is also different from those of the other American members of 

 the genus, being distinctly proetoid and conforming with that of Phaeton plani- 

 cauda and Ph. striatus, Barrande. This species, when better known, may serve 

 to establish the group designated by M. Barrande with the preoccupied term 

 Phaeton, as generically distinct from Pha ethonides. 



Distribution. From the west side of Steptoe Valley, Nevada : "Although not 

 found associated with other fossils, they are believed to belong to the Devo- 

 nian epoch." (Meek, he. cit.) 



CYPHASPIS, Burmeister, 1843. 



CyPHASPIS MINUSCULA. 



PLATE XX, FIG. 17; and PLATE XXIV, FIGS. 7-12. 



Phillipsia minuseula, Hall. Illustrations of Devonian Fossils, pi. xx, tiys. 17. 1876. 



General Form and Proportions. Outline ovate, posteriorly sub-attenuate. 

 Surface depressed-convex, sub-equally trilobate. Axis evenly tapering. 

 Length to width as 3 to 2; axial length of cephalon, thorax and pygidium 

 as 3 to 6 to 1. 



Cephalon scnii-elliptical in outline, curvature slightly changing at the genal 

 angles, which are produced into spines having an outward curve and reaching 

 almost to the pygidium. 



The facial sutures take their origin on the posterior margin near the genal 

 angles, pass obliquely forward over the palpebral lobe, thence outward and 

 forward, approximating toward the margin and terminating on the frontal 

 doublure. 



