66 TRENTON PERIOD. 



The specimens of the collection are all compressed upon shale ; but 

 there are among them examples of stipes com2)ressed in the various postm-es 

 they happened to assume when prostrated. These enable us to make out the 

 structiu-e as above indicated with comparatively little difficulty. Without 

 bearing in mind the quadiilateral fonn of the stipe, one may mistake the 

 confusion of details which the laterally -compressed specimens exhibit for 

 examples of two stipes of an ordinary Diplograptus lying parallel and com- 

 pressed together; but the adjustment and vinifomiity of the parts show 

 that they all belong to a single body. 



This species, so far as can be determined from the specimens of the 

 collection, is so closely like G. quadrimucronatus Hall, from the "Utica slate 

 formation. Lake Saint John, east from Blue Point", that I prefer to assign 

 it provisionally to that species rather than to a new one. Our specimens, 

 however, are more delicate and slender, and the mucronate points much 

 less conspicuous than they are in the typical forms. The cells are also a 

 little more prominent and the cell-apertures proportionally wider vertically. 



Position and locality. — Shales, probably of the age of those at Nonnan's 

 Kill, near Albany, New York; five miles north of Belmont, Nevada, ■p^here 

 it is associated with the three species last described. 



Class ACTINOZOA. 



Order ZOANTHARIA. 



Family FAVOSITID^. 



Genus MONTICULIPOEA d'Orbigny, 1850. 

 Monticulipora Dalii Edwards aud Haime. 



Plate IV, fig. 5. 



Chwtetes Dalii Edwards et Haimo, 1851, Monograpbie des Polypiers Fossiles, 266. 



Coral dendroid; the branches cylindrical, six or eight millimeters in 

 diameter; surface marked by small, slightly-raised mammillations, distant 

 two or tlu-ee times their own diameter from each other; calyces subequal 

 in size, about one-qiiarter of a millimeter in diameter. 



