344 BFLLETIX: MUSEUM OF COMPARATIVE ZOOLOGY. 



localities of which only a few will be considered. One of the best 

 exposures of the beds immediately above and below the Da\'ia flags 

 is that of Lau Canal. This section has been described in detail by 

 Munthe ^ and I merely wish to call attention to a few of the lithic and 

 faunal variations. At the northwestern end of the canal the lithology 

 is that of grayish blue laminated shales in which fossils — Atrypa 

 reticularis excepted — are not common. Proceeding southeastward, 

 a rising dip leads to a reef-like mass of limestone. This is composed 

 of tabulate and stromatoporoid corals and is succeeded by jointed 

 shales filled with an abundance of rh\-nchonelloids. Another small 

 coral reef follows and, after that, another mass of shales similar to 

 those first described and with an equal paucity of fossils. RhATicho- 

 nelloids are verv uncommon in the first and third shales ; but extremelv 

 abundant in the shales between the coral masses, while large specimens 

 of Atrypa reticularis are relatively common in the first and third 

 sections of shales, but are hardly present in the second. All of this 

 variation may be seen in lessthan fifty feet, and the strata in question 

 are believed to be of the horizon of the Ilionia bed. 



Another excellent place to observe horizontal lithic and faunal 

 variations is at Hoburgen klint in the higher beds of reef and other 

 limestones. In the klint the great unstratified masses of coral rise 

 many feet, and are bordered on each side by stratified crystalline and 

 other limestones of a quite different lithic and faunal aspect, the latter 

 deposits filling up the irregularities in the sides of the former. The 

 interfingering of coral and sediment and the irregular contacts are 

 ■extremely striking and instructive. These latter strata generally dip 

 away from the reef. Still another excellent place to study the varia- 

 tion in sediments is Burgen Ridge, on the northern side of which a 

 mass of hard reef limestone is underlain by shaly reef and crinoidal 

 limestone, this being limited below by the Dayia flags. On the 

 southern side, on the contrary, the rock occupying exactly the same 

 stratigraphic position consists of oolite and limestone conglomerate 

 (Plate 5, fig. 2) with pebbles up to an inch in diameter, sandy lime- 

 stone, and calcareous shales and limestones underlain by the lower 

 Sphaercodium bed and the Dayia flags. On the northern side Sphae- 

 rocodium has not been noted. All of these variations occur in about 

 one fourth mile. Another excellent locality is on the island of Storo 

 Karlso where numerous fine exposures may be seen in the sea cliffs 

 in which faunal and sedimentary variation are shown. Dozens of 



' Munthe. Sveriges geologiska unders., 1902, ser. C. no. 192, p. 9. 



