LISTS OF FOSSILS COLLECTED. 



SILUEIAN SPECIES. 



EAST SIDE OF GALLATIN EIYEE, ABOVE GALLATIN CITY, MONTANA, 

 First or upper division. 



Names. Eemarks. 



1. Lingulepis.* -. , 



2. Gonocoryplie Merely fragments. 



3. Batliyurus (?) Merely fragments. 



4. Asaphus (!) . , Merely fragments. 



Second division. 



5. Acrotreta. 



6. Lingula A very small shining species. 



Third division. 



7. Acrotreta- sulconica^^ntoi: go..] 



8. Iphidea sculptilis, Meek See description in this report. 



9. Hyolitlies gregaria, {TJieca gre- 



garia, M. and H.) Mere cast, but agrees in size dnd 



form with this species. 



10. Agnostus Mdens, Meek X 



11. Conocoryplie [Conoceplialites) 



Gallatinensis, Meek See description in this report. 



*Two specimens only of this fossil are contained in the collection. These have ex- 

 actly the outline, and agree well in most other respects with a form Professor Hall has 

 referred, doubtfully, to the shorter valve of L. pinnceformis, Owen, from the horizon of 

 the Potsdam, It also shows the same radiating strise seen on exfoliated specimens of 

 that species, and has its- beak truncated, as in Fig. 15, pi. 6, Eegents' Sixteenth Report 

 on State Cab, N. H., New York ; though casts of the internal markings, as seen through 

 the translucent shell, seem not to present a flabeiliform appearance, as in Professor 

 Hall's figuie cited, but have the same elongated trilobate outline seen in the other 

 valve of L. pinnceformis, 



t This little shell seems to be very similar to Kutorga's species, but it has the ventral 

 valve more elevated than A. gemma, Billings, and the false area marked by a distinct 

 mesial furrow, said not to be defined in latter. The larger specimens measure 0.15 

 inch from the front to the apex of the ventral valve and 0.11 inch in breadth. The 

 beak of this valve is pointed, and generally bent slightly forward. The surface is a 

 deep brownish color, shining as in Lingula, and marked by minute lines of growth. It 

 is quite probable that a direct comparison of specimens would show our species to be 

 distinct from the Russian shell. If so, I would propose to call the species A. attentiata. 



X Resembles A. pmformis, Linn., (sp.,) but has a proportionally shorter pygidium, 

 more truncated between the posterior points ; while its mesial lobe is shorter, higher, 

 and s-urmounted by a prominent node anteriorly, and more flattened and pointed be- 

 hind, without any traces of a mesial transverse furrow. Its head is still more nearly 

 like that of A. pisiformis,hnt wants the mesial furrow extending forward from the 

 glabella to the anterior margin. Its glabella is most prominent behind, where it shows 

 a tendency to swell into a little node. Surface finely granular. 



