198 bulletin: museum of comparative zoology. 



crystal form. This rock is not made up of fragments of fossils, like 

 that of the calcareous formations below. 



The leading fossil of this formation is Christiania oblonga (Pander). 

 Some large cephalopods are found, and in the Government of Petro- 

 grad, Cryptocmiites laevis (Pander) is a characteristic fossil, and 

 Echinosphaerites aiirantiuvi (Gyllenhahl) is occasionally found. 



The Reval is the youngest formation which appears in the "Glint." 



Kvckers formation. C2, (Kuckerssche schicht or Brandschiefer) 

 of Schmidt. 



The Kuckers formation takes its name from the estate of Baron 

 Toll, about five miles northeast of the railroad station Jewe; but the 

 strata are very little exposed at that locality and collecting is now very 

 poor. The same strata are reported by Schmidt to be exposed in a 

 few natiu'al sections along streams but the places ^yere difficult of 

 access and we saw the Kuckers only at the typical locality and at 

 Reval. The formation occupies the low, level land at the top of the 

 escarpment which faces the Gulf of Finland, and the numerous 

 beautiful fossils which it has produced have come from ditches dug 

 to drain this sort of land. 



The base of this formation can be seen in the extensive quarries 

 at Reval where the upper three or four feet are a bluish gray calcareous 

 shale and thin-bedded shaly limestone containing numerous cystids, 

 including Echinosphaerites aurantium, Caryocystites balticus, and C. 

 aranea. 



In the trench at Kuckers the strata consist of gray and reddish 

 earthy limestone and soft reddish shale known from its combustibility 

 as the " Brandshiefer." Schmidt has listed localities in this formation 

 all the way from the village of Djatlizy south of Gostilizy and west 

 of Petrograd to the point where it goes beneath the waters of the Gulf 

 of Finland southwest of Baltishport. Its large fauna is rather easily 

 recognized. Chasmops odini, Ceraurus spinulosus, Poramhonites 

 teretior, Plectambonites sericeus, O.voplecia dorsata, Echinosphaerites 

 aurantium, and Platystrophia lynx were the more common species seen 

 by the writer. Of these, the O.voplecia dorsata is most valuable as a 

 cosmopolitan form, but, in Russia, confined apparently, to this horizon. 



Schmidt estimated the thickness of the Kuckers at from thirty to 

 fifty feet. 



Itfer formation. C3 (Itfersche schicht) of Schmidt. 



This member is named from an exposure on the estate of Baron 

 Wrangel at Itfer, northeast of \Yesenberg. This exposure, a small 

 quarry, is now completely overgrown and nothing is to be seen. I 



