While on later Cretaceous deposits in Iowa. 233 
age; and at my request he kindly sent them to me for examina- 
tion. The fossils consist of molluscan remains, which are im- 
bedded in fragments of firm ferruginous sandstone; and these 
fragments indicate that they are portions of highly fossiliferous 
strata. The specimens are all more or less imperfect; but the 
generic character of the greater part of them is satisfactorily 
recognizable, and a part of them have been specifically identified 
with published forms. The following is a list of the forms so 
far as they have been generically determined. Besides those 
mentioned in the list, two or three other forms are indicated by 
small fragments of shells. 
List of Spkcies. 
Inocerainus ? 
Pinna lakesi White? 
Syncyclonema rigida Meek and Ilayden? 
Nucula ? 
Callista? ? 
Corbula inornata M. and H. 
Dentalium ? ,^ 
Chemnitzia cerithiformis M. and H. 
Pseudobuccinum nebrascene M. and K. 
Lispodesthes: haworthi sp. nov. 
The specimens representing Inoceratnus are mere fragments, 
giving no indication of the form of the shell, and therefore none 
of its specific identity ; but they show the characteristic shell- 
structure of that genus. The Pinna is represented by a number 
of fragments which I have little doubt represent P. lakesi 
White, from the Fox Hills group of northern Colorado.' The 
single specimen referred to Syticyclonenia rigida"^ is imperfect, 
but the identification is probably correct. The specimen re- 
ferred to Nucula shows little or nothing of the external form of 
the shell, but the characteristic dentition is discernible. Some 
small separate valves, evidentlv belonging to the Veneriidffi, are 
referred doubtfully to Callista. Corbula inortiata^ is somewhat 
satisfactorily identified. The Dentalium is one of those com- 
' See 12th Ann. Rep. U. S. Geol. Surv. Terr., p. 17, pi. 11, fig. i. 
' U. S. Geol. Surv. Terr., vol. ix, p. 27, pi. 16, figs. 5, a b. This form was 
originally found in the Fort Pierre group, but it lias since been found in 
strata of the F"ox Hills group. 
' U. S. Geol. Surv. Terr. vol. ix, p. Zi,^, pi. 30, figs. 4 a-d. 
