MARYLAND GEOLOGICAL SURVEY 351 



Genus BUMASTUS Murchison 



BUMASTUS TRENTONENSIS Emmons 



Plate LI, Figs. 30-33 



Bumastus trentonensis Emmons, 1842, Nat. Hist. New York, Geol., vol. ii, 



p. 390, fig. 1. 

 Bumastus trentonensis (part) Clarke, 1897, Geol. Minnesota, vol. iii, pt. 2, 



p. 718. 

 Bumastus milleri Raymond and Narraway, 1908, Ann. Carnegie Mus., 



vol. iv, p. 249, pi. Ixi, figs. 9, 10, pi. Ixii, figs. 3-5. 



Description. Emmons' figure of his type specimen of Bumastus tren- 

 tonensis represents an example with eight segments to the thorax. Before 

 this specimen could be restudied it was lost and the validity of the name 

 has been questioned. It is unnecessary to enter into a history of the 

 synonymy of this species, as this was fully discussed in 1908 by Raymond 

 and Narraway. However, a species of Bumastus with eight segments 

 occurs in the Trenton limestone of New York which, according to the 

 present arrangement of species of the genus, has no name. This species 

 agrees with Emmons' figure fairly well and it seems reasonable to retain 

 his name of Bumastus trentonensis. 



Occurrence. MARTINSBURG SHALE (Sinuites bed). Chambersburg, 

 Pennsylvania. Trenton limestone of New York. 



Collection. U. S. National Museum. 



Family DIKELOCEPHALIDAE 



Genus SAUKIA Walcott 

 SAUKIA STOSEI Walcott 

 Plate XXVII, Figs. 6-8 



t Saukia stosei Walcott, 1914, Smithsonian Misc. Coll., vol. Ivii, No. 13, p. 384, 

 pi. Ixix, figs. 3-5; pi. Ixx, figs. 12, 12a. 



Description. " This species belongs to the 8. pepinensis form of 

 Saukia, and is most nearly related to Saukia fallax, but it has a propor- 

 tionately larger palpebral lobe. The associated pygidium differs from the 

 pygidium found with 8. fallax in Texas in having a longer axial lobe, 

 and the surface is strongly granulated instead of being smooth as in 

 S. fa llax." Walcott. 



