Geology and Mineralogy . 263 



costata McCoy (near P. gibbosus W. & S., of the Trenton), Orthis 

 chaungzonensis O and irravadica (both new Plectorthis related 

 to P. triplicatella), Clitambonites of the Baltic C. squamata 

 group, Porambonites intercedens Pander (Baltic). Of trilobites 

 the genera represented are Remopleurides, Encrinurus, Calymene, 

 and Arnphion (=Pliomera). These species are said to be from 

 " one set of beds " which the author is not disposed to correlate 

 definitely. To the reviewer, they seem to agree fairly well with 

 the Baltic foimiations marked C by Schmidt (Echinosphaerit, 

 Kuckurs and Itfer zones), and though less clearly, but still with 

 considerable evidence, with the American interior Galena and 

 Trenton formations. 



Recently Weller has added other Baltic types, as Hemipro- 

 nites, Asaphus (5 species), and Megalaspis, collected by Willis 

 and Blackwelder from the Kinsinling limestone, province Ssich'- 

 uan, China. The age, he states, is " approximately equivalent to 

 the fauna of the Trenton limestone of North America." In 

 Shantung Ormoceras and Gonioceras occur according to Crick. 

 This evidence points clearly to an intimate relationship between 

 these Asiatic faunas and those of the Baltic region. On the 

 other hand, it is also clear that the interior American Mohawkian 

 faunas are of the Pacific realm, but with a development that 

 readily separates them into a distinct province. In further sup- 

 port of this view is the discovery by Ulrich and Bassler of Echi- 

 nosphaerites and Cyclocrinus in Virginia. 



Silurian (Namhsim sandstone). — The more characteristic of 

 the 38 species described are Mimulus aunglokensis (new), Orthis 

 rustica, Bilobites biloba (exceedingly common), Platystrophia 

 biforata, Atrypa reticularis, Spirifer sulcatus, Niicleospira pisum, 

 Encrinurus konghsaensis (new, near E. punctatus), Calymene 

 blumenbachi, and Dalmanites longicaudatus orientalis (new). 

 This fauna is regarded "as homotaxially equivalent" with the 

 Wenlock. • 



Silurian (Nyaungbaw formation). — These beds yield frag- 

 ments of a Scyphyocrinus, Camarocrinus asiaticus (near C. idrichi 

 of Oklahoma), and a small Orthoceras. The crinoid material 

 has the development of the Silurian etage E2 of Bohemia. La 

 Touche "is inclined to put the Nyaungbaw beds at the top of the 

 Ordovician," but with this correlation the reviewer does not agree 

 (he is aware that Fritsch has recently described Camarocrinus 

 quartzitarum from the middle Ordovician of Bohemia). The 

 paleontologic evidence clearly places this formation in close asso- 

 ciation with the Zebingyi beds. 



Power Devonian (Zebingyi formation). — Among the 23 species 

 the more important are Monograpttts dubius Suess, M. cf. riccar- 

 tonensis Lapworth, Atrypina sub-globidaris (fig. 31 seemingly 

 the young of Atrypa reticularis, 32, 33 represent a large Atry- 

 pina, but the specific name is a misnomer, as no known species is 

 globular or even biconvex), Tentaadites elegans (in Bohemia 

 Fl — Hi = Lower Devonian), Styliolina cf. laevis, Dalmanites 



