84 TRANSACTIONS OF THE [pEc. 16, 
eighth of a mile to the south, the same layers reappear in the 
much more extensive Rathbone Brook section. 
III. RATHBONE Brook Section—130 B. 
The brook flows into West Canada Creek, near the Black 
River exposure ; and the lowest beds upon it, west of the road- 
way must occupy a position not far above the Black River. The 
- brook would repay close stratigraphic study, as its meandering 
course with numerous falls affords a continuous section of con- 
veniently exposed layers for nearly two and one-half miles up 
the ravine between the hills. The beds dip at about 10° S. 
40 W. In order to obtain the relations of the lowest Trenton. 
collections were limited on this occasion to that portion of 
the stream between the road running parallel to the creek and 
the first bridge on the hill road running at right angles to it, a 
distance of possibly half a mile, up hill. In ascending order 
these zones are: 
B: 1. Thin bedded shaly light gray limestone, lowest 
beds seen on the south side of the brook, with black 
partings and fragmental remains in the upper portion, 
otherwise nearly barren. 12/ 
Strophomena planwmbona. Prasopora lycoperdon of 
Orthis testudinaria. large tubed form. 
Plectambonites sericea. Calymene senaria. 
Stenopora fibrosum, ventricose variety. | Asaphus platycephalus. 
Trinucleus concentricus. 
Ceraurus pleurexanthemus. 
2. Lowest layers on north side of brook. Gray,coarsely 
crystalline with extremely abundant Prasopora lyco- 
perdon, growing up in large cylindrical masses. 1 td 
Also fragmentary remains of 
Orthis ( Platystrophia, biforata a. 
Plectambonites sericea ¢. Bellerophon bilobatus. 
Trinuculus concentricus ¢. Murchisonia milleri. 
Calymene senaria ec. Holopea symmetrica. 
Ceraurus pleurexanthemus ©. Rafinesquina alternata, 
Stenopora fibrosum. coarsely ribbed variety. 
Monticulipora, branching species. Crinoid stems, occasional. 
3—4. Lower part of first fall. Light gray, pure and 
very finely crystalline or sandy, with regular cleavage ; 
nearly all the fossils fragmentary. DAN 
Prasopora lycoperdon, large celled 
form c. Trematis terminalis. 
Holopea symmetrica. Lingula fragments. 
Stenopora fibrosum. Rafinesquina alternata. 
