i62 Cincinnati Society of Natural History. 



Genus 7. — Dawsoxia, Nicholson, 1873. 



Horny or chitinous capsules of a rounded, oval, conical, or 

 campanulate shape, furnished in most cases with a little spine 

 or mucro, and having a marginal filament exactly resembling 

 the solid axis of a graptolite. The marginal fiber sometimes 

 complete, sometimes ruptured opposite to the mucro. The 

 mucro sometimes apparently wanting, sometimes marginal, 

 sub-marginal, sub-central or central. The surface smooth or 

 concentrically striated. (Annals and Mag. Nat. Hist., 4th .ser., 

 vol. II, 1873, p. 139). Lockcia, U. P. James. The Paleon- 

 tologist, 1879. 



Remarks. — The above name was proposed by Dr. Nicholson 

 for certain bodies found associated with graptolites in vScot- 

 land and in Canada, which he considered the ovarian capsules 

 of graptolites of different species. The generic name, Lockcia, 

 was propo-sed for similarly shaped bodies found at Cincinnati, 

 and supposed to be the remains of marine plants. There can 

 be no question that the bodies under consideration are not 

 plant remains. Their resemblance to figures and descriptions 

 of Dajcsoiia cause them to be considered as synonymous with 

 that genus. I find, however, that in 1868, Dr. Daw.son refers 

 as follows to a species of trilobite. After describing Micro- 

 discus daivsoni, Hartt, he says: " Mr. Hartt had originally de- 

 scribed this species under the new generic name of Da-wsonia, 

 but Mr. Billings regards it as a species of Microdiscus of 

 vSalter." (Acadian Geology, 1868, p. 655). Whether under 

 these circumstances the name Dawsonia was pre-occupied by 

 Hartt is a question to be decided by others. In case it be de- 

 cided in the afiirmative, it is evident that Lockcia must be 

 used. For the present we shall u.se Dazcsonia, Nicholson. 

 The description o{ Lockcia is as follows: Elongated, convex, 

 obtuse or sharp-pointed bodies, seed-like in appearance, 

 slightly attached to the surface of the rock, with or without a 

 longitudinal depression. (The Paleontologi.st, 1879, p. 17). 

 Only one species is known from these rocks, as given below. 



1). siijQUARiA, V . P. James (.sp.) 1879. 



Convex, elongated elevations from one-eighth to one-half 

 an inch long, one-half to one and one-half lines broad at base, 

 and one-half to one line high in center; sloping and tapering 



