58 Pemer & Kodym — Zonal Division and 



shape, 2-15 inches in diameter), often forming almost con- 

 tinuous beds ; thin beds of shaly limestone and compact 

 or crystalline limestone often alternating with shales are 

 also a common feature in many localities. Some- 

 times these calcareous intercalations contain trilobites, 

 brachiopods, various molluscs, etc., and graptolites 

 in them are often preserved "en relief." As already 

 suggested, these intercalations do not occupy a definite 

 horizon ; in some sections they are not to be met with until 

 the much higher beds. Some of these limestones are 

 very similar to those from Barrande's Bande E 2 , and 

 many fossils which are confined to these E x limestones 

 have indeed been erroneously cited as occurring in E 2 . 

 Three zones can be distinguished in E^: 



a. Zone with Monograptus spiralis Gein. var. subconi- 

 cus Tornq. — Dark brown fissile shales, or grayish and 

 dark flagstones ; no calcareous nodules present. Char- 

 acteristic graptolites are: Monograptus priodon Brn., 

 M. vomer inus Nich., M. spiralis Gein. var. subconicus 

 Tornq., M. griestonensis Lapw., M. sacculiferus n. sp., 10 

 and Retiolites geinitzianus Barr. 



b. Zone with Cyrtograptus murchisoni Carr. — Shales 

 of similar lithological character to those in the former 

 zone. First appearance (in the same localities) of cal- 

 careous nodules. In the western part of Barrande's 

 "Silurian basin" 11 these shales alternate with dark com- 

 pact limestones or light crystalline limestone ; the latter 

 occurrence seems to be in connection with the nearby coral 

 reef, forming an almost continuous seam between Tach- 

 lovice and Tetin, and reaching vertically into higher zones 

 (see section on the coral-reef facies). The shales of this 

 zone yielded: Monograptus priodon Brn., M. vomerinus 

 Nich., M. latus M'Coy, M. kettneri n. sp., M. remotus 

 Tornq., Cyrtograptus murchisoni Carr., M. purkynei 

 n. sp., M. centrifugus n. sp., M. insectus n. sp., M. evolvens 

 n. sp., Retiolites geinitzianus Barr., and Stomatograptus 

 grandis (Suess). In the limestone and calcareous shales 

 and mudstones at Lodenice I have found, in association 



10 In recent years many new graptolites have been found in E 1? descriptions 

 of which are being prepared by my pupil and collaborator, .0. Kodym. 



11 E. Kettner has proposed and is using the term ' ' Barrandien ' ' for the 

 area in Bohemia in which are developed the Paleozoic rocks included in 

 Barrande 's old and inappropriate term, ' ' bassin Silurien du centre de la 

 Boheme, " viz., his Etages A-H (Algoukian to Devonian). 



