576 SCIENTIFIC RECORD FOR 1884. 



Walcott, C. D. — Paleoutology of the Eureka District. (Monographs 

 of the United States Geological Surv-ey, vol. viii, pp. i-xiii and 1-298, 

 pis. i-xxiv, and seven figures in the text. Washington, 1884.) 

 Gives an account of the very interesting paleozoic fauna of this dis- 

 trict. The first chapter contains a fair summary of the results. A com- 

 mingling of Upper Devonian and Lower Carboniferous fossils occurs. 

 The discussion of the development of Olenelkts Howelli is very interest- 

 ing. The succession in the faunal series from the Olenellus beds, 

 through a well-defined fauna of the character of the Potsdam group of 

 New York and the Mississippi Valley, to one containing a mixture of 

 Cambrian and Silurian types passing upward to a fauna comparable 

 to that of the Chazy and Calciferous groups, is shown. The transi- 

 tion is said to be very gradual, and such as would occur where there 

 had been no marked physical disturbance. Here is another instance of 

 the occurrence of passage beds between faunas before considered per- 

 fectly distinct, and it is very interesting to note this fact in our earliest 

 faunas, which is so common in our later ones. 



The author gives carefully prepared systematic lists of the fossils in 

 each formation and a paleozoic section of Nevada showing the vertical 

 range of the genera. Two new genera are described, Schizambon, referred 

 to the Siphonotretidae, from theL. Silurian Pogonip group and ZaptycJiius, 

 an auricula-like shell, from the Carboniferous. The author describes one 

 hundred and seventy-three new species, of which thirty are from the 

 Cambrian: Acrothelef diehotonia, SceneUa ? conula, Kutorgina ichitjieldi, 

 K.prospectensis, OrtJds eureJcensis, StenotJieca elongata, Agnostus riehmond- 

 ensisj A. seclusus, Olenellus iddingsi, Dicellocephalus nasutus, £>. richmond- 

 ensis, D. f angustifrons, D. iole, D. mariea, D. f expansus, Ftychoparia ? 

 prospectensis^ P.? linnarssoni, P. [Solenopleuraf) hreviceps, P.% {Soleno- 

 pleura f) pernasutus, P. [Euloma) dissimilis, P. {Eulonia) Occidentalis, P. 

 {Euloma)similis, P. (Euloma) affinis, P. {Euloma) laemceps, P. {Petro- 

 cephalus) occidena, Anomocare f parvum, Agruulos f glohosus, Arethusma 

 anicricana, Ogygia f spinosa^ 0. f prohlematica. From the Pogonip 

 group of the Lower Silurian thirty-one species are described: Beceptaeu- 

 lltes mamillaris Newb. n. sp., R. elongata, B. elUpticus, Obolella ambi- 

 giia, Schizambon typicalis, Orthis hamburgensis, 0. lonensis, Streptorhyn- 

 cus minor, TeUinomya f hamJ)urgensis, Modiolopsis occidens, M. pogoni- 

 pensis, Pleurotomaria lonensis, Maclurea annulata, 31. subannulata, M. 

 carinata, Metoptoma pMllipsi, M. f analoga, Coleoprion minuta, Hyolithes 

 vamixemi, Dicellocephalus Jinalis, D. inexpectans, Ptyclioparia ? annectans, 

 Bathyurus f tuberculatus, B, f congeneris, B. f simillimus, Gyphaspis f 

 brevimarginatus, Amphion nevadensis, Symphysurus f goldfussi, Barran- 

 dia f McCoyi, Illaenurus eurelcensis, Asaphus caribounensis. From the De- 

 vonian sixty-one new species are described : Palaeomanon roemeri, Lin- 

 gula alba-pinensis, Lingula lonensis, L. wliitei, PhoUdops bellula, P. quad- 

 rangularis, Ihercidium devonicmn, Chonetes macrostriata, C. filistriata, 

 Productus [Productella) hallanus, Productus hirsutiforme, Cyrtina david- 



