jg NEW YORK STATE MUSEUM 



DESCRIPTION OF SPECIES OF THE DALHOUSIE FORMATION 



Spirorbis sp. 



Specimens common, attached to various shells. 

 Horizon. Nos. 9, 13. 



Pterygoius sp. 



Plate i, figure 8 



There have been found several fragments of large segments of a 

 Pterygotus but no other parts. These show a coarsely scaly surface, 

 Horizon. No. n. 



Phacops logani Hall van gaspensis Clarke 



See N. Y. State Mus. Bui. 107. 1907. p. 165 and this memoir, pt i, p. 119, pi. 10, fig. 5, 6, 10-16 



A few parts of a Phacops show no critical characters by which they can 

 be distinguished from the form occurring on the Gaspe Forillon. 

 Horizon. No. 1 1. 



Dalmanites micrurus (Green) 



Plate i, figures 1-3 

 See pt i, p. 120 



The specimens both of cephalon and pygidium, which are identified 

 with this species, are larger than those of the Grand Greve limestone 

 and in the pygidium the pleurae are very clearly sulcate and tubercled. 

 These, however, are probably but slight differences and with the New York 

 types they are quite consonant. 



Horizon. No. 1 1 . 



Bronteus barrandii Hall var. major Clarke 



Plate i, figure 7 



Bronteus barrandi.i Hall var. m a j o r Clarke. N. Y. State Mus. Bui. 107. 1907. p.i6y 



A pygidium with the structural details of B . barrandii, but having 

 many times the size distinctive of that species in New York and Gaspe. 

 It has the short axis, broad median rib and seven lateral ribs on each 

 side, all becoming obsolete on the smooth border. There is here no 

 structural variation from the specific type but a noteworthy distinction 

 in expression. 



Horizon. No. 10. 



