FORMATIONS OF ORDOVICIAN AGE. +1 
10. Lsotelus gigas De Kay. 
11. Bumastus trentonensis (Kmim.). 
12. Calymene senaria Con. 
13. Plerygometopus callicephalus (Hall). 
14. Leperditia fabulites (Con.). 
The fossils from this locality are practically in situ. The presence 
of such species as Streptelasma corniculum, Orthis tricenaria and 
Plerygometopus callicephalus, associated with Dalmanella subequata, 
Hehcotoma sp. and Leperditia fabulites, indicates the position of the 
~ beds to be at the top of the Black River horizon or at the very base 
of the lower Trenton. Receptaculites occidentalis is an interesting 
species which was not found in the Jacksonburg section, but which 
occurs frequently in New Jersey, and seems to mark a faunal zone 
at the very summit of the Black River horizon. 
Locality 135 A.—This locality lies about one-fourth of a mile south 
of the slate quarry at Newton.* The fossils were collected from loose 
masses of limestone on a barren knoll in the midst of the cultivated 
fields, and the following species have been identified : 
1. Prasopora simulatria Ulr. 
2. Rhinidictya sp. undet. 
3. Plectambonites sericeus (Sow.). 
4. Plectorthis plicatella (Hall). 
5. Dalmanella testudinaria (Dal.). 
6. Parastrophia henuplicata (Hall). 
Zygospua recurvirostris (Hall). 
8. Tetranota bidorsata (Hall). 
9. Bumastus trentonensis (Kmm.). 
10. Calymene senaria Con. 
11. Pterygometopus callicephalus (Hall). 
This fauna indicates the middle portion of the Trenton limestone 
proper. The extreme basal Trenton species, such as Streptelasma 
corniculum, Orthis tricenaria, Dinorthis pectinella and Rhynchotrema 
imequivalvis, are all absent, but Parastrophia hemiplicata, which char- 
acterizes the zone next above, is one of the common species, and is 
associated with Tetranota bidorsata, which occurs somewhat higher in 
the Jacksonburg section. From the nature of the locality fossils from 
more than one bed in the formation have become mingled in the 
collection. 
* Near locality marked 14, Map No. 17, p. 75, loc. cit. 
