REPORT OF THE STATE PALEONTOLOGIST 1902 941 



his description, and may therefore have had a like shape. Our 

 specimen is also somewhat larger than the Cape Breton form. 



Acrotreta bisecta Matthew. There also occur types of an Acro- 

 treta in the Clonograptus bed, the pedicle valve of which has 

 been noticed only in a very much compressed state but still ex- 

 hibiting the subcentric pedicle perforation. The brachial valve 

 possesses the long, high, posteriorly enlarged (or dividing? in 

 many specimens) median ridge, extending the entire length of 

 the shell, and also on the cast, at least one pair of the minute 

 pits, features which Matthew considered characteristic of his 

 species Acrotreta bisecta, a form from the Dictyonema 

 shales at McLeod brook, Cape Breton. 1 As our form also agrees in 

 general outline and dimensions with the Cape Breton species, 

 it may well be considered as identical with the latter. Mat- 

 thew has also recognized this species among the brachiopods 

 collected in the Dictyonema shale at the Navy island, St John 

 N. B. as the form which he had formerly described as Acro- 

 treta baileyi. 2 



Acrotreta cf. belti (Davidson) Matthew. There occur small 

 orbicular corneous brachiopod shells in the Clonograptus bed, 

 whfch on account of their small size and compression offer con- 

 siderable difficulty to a definite determination. The pedicle 

 valve shows a small circular pedicle perforation, the brachial 

 valve, which is well preserved, three narrow septa and pos- 

 terior muscle impression, as one finds in Linnarssonia 

 transversa Walcott. As the latter species has lately been 

 reunited with Acrotreta by Walcott 3 this form is probably also 

 referable to Acrotreta. It seems to us to be identical with the 

 minute shells found by Matthew in the Dictyonema beds (divi- 

 sion 3c) at Navy island, St John harbor, and doubtfully referred 

 by him to the Lower Tremadoc form, Linnarssonia 

 belti Davidson. 4 It agrees at least with this St John fossil 

 in size, outline and horizon. The internal characters of the latter 

 are not well known. 



1 Nat. Hist. Soc. New Brunswick. Bui. 19. 1900. 4:275, pi. 5, fig. 5a-g. 



a Hoy. Soc. Can. Proc. and I rans. 1891. 9:43. 



8 U. S. Nat. Mus. Proc. 1902. 25: 577. 



4 Roy. Soc. Can. Proc. and Trans. 1891. 9: 42. 



