v^^TW.^ CRETACEOUS FOSSILS OF COALVILLE, UTAH. 237 



remarlcably modem in type, and, seen separately, and without any knowl- 

 e<lffe to tlie contrary, no paleontoloj^ist would be warranted in referring 

 tliein to an earlier peiiod than the Tertiary. 



Tlie e^•idenec of their Cretaceous age, however, is unquestionable, 

 tliere being more than 1,000 feet in thickness of marine Cretaceous strata 

 i-estiug ui)on them ; and more than an equal thickness of Cretaceous 

 strata lies beneath them. 



30. Pliysa carletoni Meek. 



The ligure of this species in another part, of this volume shows plainly 

 ita modern t,>i)e. For fuither remarks concerning it and its associates, 

 see Xo. 29. 



31 . Pliym ? 



This is possibly identical v/ith P. carletoni. See a figure of it in another 

 ])art of this volume ; and also remarks under No. 29. 



32. Xcritina hannistcri Meek. 



This is apparently a typical Neritina. See under ^o. 29 for general 

 ixjmarks upon its associates. 



33. J^critina pisum Meek. 



This is very like the nest following species, but it is probably distinct. 

 It is from a calcareous sandstone layer in the first ridge of I\Ir. Meek's 

 section, associated with Nos. 34, 37, 38, and other species. Although it 

 i« of the same type as No. 32, its associates are all marine forms. 



34. Kcrit'ina pisiformis Meek. 

 See remarks under No. 33. 



35. NerUina ( Vclatella) bellatula Meek. 



JVIr. IMeek discovered this species together with No. 36 in stratum No. 

 10 of his section at Coalville, associated with other brackish- and fresh- 

 water forms. See remarks under No. 29. Together with Nos. 3G, 37, and 

 38, it belongs to a section of the genus Neritma^ to which Mr. Meek gave 

 the subgeueric name of Vclatella. Some of the associates of Nos. 35 and 

 30 are both brackish- and fi-esh-water forms, but those of Nos. 37 and 38 

 axe all marine forms. The only other known species of this subgenus is 

 K. ( r.) baptista White, from the Laramie strata at Black Buttes Station, 

 where its associates arc both fresh- and brackish -water forms. In vol. 

 iv, Expl. & Siu\ West of the 100th Merid., I described and figured a 

 form from Cretaceous rocks of Utah, which! referred to J\^. ( F.) carditoi- 

 dcs Meek, but vvhich possibly belongs to another, but closely allied, spe- 

 cies. Its associates there are understood to be marine forms only. 



30. Neritina ( Vclatella) carditoidcs Meek. 

 See remarks under Nos. 29 and 35. 



37. Neritina ( Velatclla) patelliformis Meek. 

 See remarks under Nos. 33 and 35. 



38. Neritina ( Vclatella) patelliformis var. wehercnsis Wliite. 

 Sec figures and descrii)tion in another part of this volume. 



39. Eufpira coalvillensis WlntQ. 



Found only at Coalville and in the first ridge of INIr. Meek's section. 



40. Gyrodcs dcprcssa Meelc. 



This well-marked species has been found only in the form of casts, and, 

 so far as I am avrare, only from the sandstones of the second ridgo of 

 Mr. ]\Ieek's section. 



