46 



deeply divided. All the margins of the lobes and sinuses are charac- 

 terized by small, rounded serrations. Siphuncle of moderate size, mar- 

 ginal and situated between the lines of nodes. 



The distinction between this and the preceding species consists in 

 its large size, more robust habit, and thicker shell, and in the more 

 distant and much more complicated septa. It is still further removed 

 by these characters from P. Mortoni M. & H., as well as by the simple 

 ridges. 



ITormation and locality. — In limestone of the Fott Pierr^ gfonp, oil Old 

 Woman's Fork, Black Hills. 



LIST OF FOSSILS DBSCKIBBD IK THE EEPOET OF THE* 

 PALEONTOLOGY OP THE BLACK HILLS. 



POTSDAM GKOUP. 



Name. 



PLASTY, 



Faleeochorda prima, D. sp 



FalsBopbycus occidentalis, n. sp 



sp, undet 



INOERTBCEDES. 



Scolitlms, sp. ?..i. 



BrACHIOPODA. 



Siingnlepis pinnafomiiB, Owen 



cuiieolns, n. sp 



pbraittetiuatns, ti. sp 



Dakotbn&is, Meek & Hayden . . 



Obolas ? peetenoides, Whitf 



Obdlella pdlita.Hall 



Obolella ndna, M. t&. H 



CRUSTACEA. 



Crepicephalus (Loganellas) centralis, n. sp 

 planus, n. sp . 



Locality. 



Head of Red Water Valley. 

 Do. 

 Do. 



Warren's Peak. 



Red Canon Creek. 



Do, 



Do. 

 Castle Creek. 



Do. 

 Red Water Cafion. 



Do. 



Castle Creek. 

 Do. 



JURASSIC. 



RADIATA. 



Asteiias? dnliium, n. sp 



Fentacrinus asteriscas, M. & H. 



BRACHIOPODA 



Iiingula brevirostris, M. & H... 

 Ehynchonella myrina, H. &. W 



Spear's Pork of Red Water Creek. 

 Big Horn Monntalos. 



Spear's Fork of Red Water Creek. 

 Red Canon Creek. 



