7C 
581 Riggs (Elmer S.). A new species of Dinictis from the White 
lliver Miocene of Wyoming. 
Kans. Univ. Quart., vol. iv, pp. 237-241, fig. 1, 1896. 
Describes and figures the skull of Dinictis paucidens and compares it 
with other species of Dinictis. 
5S2 Roberts (I). E.). Note on the Cretaceous formations of the eastern 
shore of Mary laud. 
Johns Hopkins Univ. Giro., vol. xv, pp. 16-17, 1896. 
<;ives lists of fossils found at various localities. 
583 Roeth (A. J.). The lead and zinc fields of Wisconsin. 
Eng. and Mg. Jour. vol. lxi, pp. 88-89, 1896. 
Descrihes briefly the occurrence of lead and zinc in AVisconsin. 
58 4 Rominger (0.). Geological report on the Upper Peninsula of 
Michigan, exhibiting the progress of work from 1881 to 1884. 
Iron and copper regions. 
Mich. Geol. Surv., vol. v, Pt. I, pp. 1-179, with map and geologic cross 
sections. 1895. 
Descrihes the character and distribution of the granitic and dioritic 
rocks, the lithologic character, succession, and structure of the iron ore 
and Keweenawan groups. Includes descriptions of some of the iron and 
copper mines. 
585 Ruedmann (R.). Note on the discovery of a sessile Conularia— 
Article I. 
Am. Geol., vol. xvii, pp. 158-165, pis. viii-ix, 1896. 
Describes material from the Utica shales and discusses the evidence 
indicating that the Conularia?, with their cuneiform appendages and 
similar bodies attached to Trochonema, belong together. 
580 Note on the discovery of a sessile Conularia— Article IT. 
Am. Geol., vol. xviii, pp. 65-71, pi. ii, 1896. 
Describes and figures the basal appendage of a Conularia gracilis. 
587 Russell (Israel C). Igneous intrusions in the neighborhood of 
the Black Hills of Dakota. 
Jour, of Geol., vol. iv, pp. 23-43, pis. i-iii, 1896. 
Describes an occurrence of igneous intrusions in sedimentary rocks, 
(littering in form from either laccolites or volcanic rocks. Gives a 
detailed description of the several igneous masses. 
588 On the nature of igneous intrusions. 
Jour, of Geol., vol. iv, pp. 177-194, 1896. 
Describes the different forms of igneous intrusions as shown by 
intruded sheets, laccolites, plutonic plugs, and great dome-shaped uplifts, 
and discusses tbeir origin. 
s. 
589 SafFord (flames M.). A new and important source of phosphate 
rock in Tennessee. 
Am. Geol., vol. xviii, pp. 261-264, 1896. 
Describes the occurrence of the phosphate material and the character 
of the Trenton formation in which it is found, and gives its chemical 
analysis. 
