153 ANNALS NEW YORK ACADEMY OF SCIENCES 



toward the southwest, the best locality for them being the vicinity of 

 Phoenixville, Pa., particularly the Keacling Eailroad tunnel at that place, 

 now largely inaccessible. A detailed list of the fossils from this locality, 

 as originally published by Wheatley, is given below. 



The fossils are more frequent in the shaly layers than in the massiVfe 

 ones. The collector in the field will usually find traces of fish scales and 

 crustaceans in the blackest shale layers. A few well preserved specimens 

 have been taken from the densest beds of gray argillite, as shown by the 

 cycad fronds obtained from Carversville, Montgomery Co., Pa.,' and the 

 splendid frond of a cycad, Otozamites latior (Saporta), found in one of 

 the Princeton quarries about 1884, and now on exhibition in the geo- 

 logical museum at Princeton University. 



The most important fossils of the Lockatong are the following : 



Scales of ganoid fishes, usually separated, but at times in groups in 

 black shale layers. Ehomboidal, enamelled scales, either smooth and 

 without ornamentation (Semionotiis (sp?)) or ornamented with a pat- 

 tern of deep furrows and ridges {Ptycliolepis (sp?)). One maxillary 

 of Semionotus was found, together with scales and head parts of this 

 fish, in a limy layer near Wycombe, Bucks Co., Pa. 



Estheria. Shells of a phyllopod crustacean. Longest diameter about 

 half a centimeter, usually appearing as flattened disks on the surfaces of 

 black shale. The shells are ornamented with numerous concentric rings, 

 between which in some cases can be seen the ''^reticulate interspaces'' de- 

 scribed by T. Eupert Jones. ^ These are abundant in some layers in the 

 southwestern part of the area, as at Phoenixville, and are usually asso- 

 ciated with ostracods (Candona rogersi; see description in Jones's mono- 

 graph). Most of the crustaceans found are Estheria ovata. Other spe- 

 cies of Estheria have been reported by C. M. Wheatley, T. E. Jones and 

 T. A. Conrad. Among the specimens collected by the writer, the species 

 E. ovata only has been identified. Some tiny shells found at one locality 

 are doubtless the same form in an early stage of development. Witli the 

 estheriae and ostracods the scales of Semionotus often appear, as at 

 Wycombe. 



Certain layers of shale are found to carry numerous microscopic black 

 spines, which do not correspond with those of the ganoid fishes or with 

 those of echinoderms. They may be the setae or parapodia of the worms 

 whose borings are often seen in the sandy layers. They are, however, too 

 small for positive identification. 



Cycad fronds occur rarely, as described above. 



' Brdwx, a. p., "New Tyads and Conifers from the Trias of Penns.vlvania." Proc. 

 Acad. Nat. Sci. Phila. for 1011. pp. 17-21. 



* A Monograph of the Fossil Estherise, Paleont. Soc. Lon., 1802. 



