part 2] ANNIVERSARY ADDRESS OF THE PRESIDENT. lxxxiii 



Among the wonderful relics of the rich invertebrate fauna in 

 the Burgess Shale (of Middle Cambrian age) in British Columbia, 

 Dr. Walcott found several specimens which he believes to be the 

 remains of algae entombed in tbe mud of a lagoon or small bay in 

 close connexion with the shallow Cambrian sea. Many of th 

 fossils are preserved as shiny black films on the hard shale, and 

 in thin sections of the matrix minute cell-like bodies were seen in 

 chains and groups. Most of the forms described are assigned to 

 the Cyanophycese or Blue-Green Algse, while others are considered 

 to be members of the Red Algae. The delicate, branched, fila- 

 mentous form named Warpolia spissa, admirably shown on two 

 pieces of shale presented to the Sedgwick Museum by Dr. Walcott, 

 does undoubtedly, as he says, bear a striking superficial resemblance 

 to the recent genus Gladophora. By the employment of a very 

 useful method, which will be described elsewhere, my son-in-law 

 (Mr. J. Walton) was able to examine the surface of a piece of the 

 Burgess Shale under the high power of a microscope. He found 

 that the filaments consist of semi-transparent sheaths occasionally 

 broken by transverse cracks into portions which are too irregular 

 in size to be structural : the sheaths show a longitudinal striation 

 due to the presence of one or more narrow, opaque bands. He is 

 inclined to interpret the black threads as filaments of some lowly 

 organized plant similar to the existing Oscillatorice or other Blue- 

 Green Algse enclosed in a mucilaginous sheath. Another piece of 

 shale shows an impression of a species of the common Burgess- 

 Shale genus Morania represented by impressions of membranous 

 sheets with irregularly scattered perforations ; and, as the author 

 of the genus suggests, very similar in texture and general appear- 

 ance to species of the recent genus Nostoc. Chains of small, 

 spherical bodies seen in thin sections of the rock on which Morania 

 eon^uens is preserved are tentatively regarded by Dr. Walcott as 

 remains of the cellular structure of the alga. The evidence is not 

 convincing; but, as Walcott says, it is difficult to conceive of 

 the curved lines of minute balls as inorganic in origin. The 

 Blue-Green Algae are among the most primitive of living plants, 

 and they live under very diverse conditions, on land, in fresh 

 water, in the sea ; they can adapt themselves to higher tempera- 

 tures than those that are tolerated by the great majority of plants. 

 I recall a striking scene between Northern Australia and Java : 

 broad lines of cinnamon-brown, stretching as far as the eye 

 could see, on the blue surface of the Pacific, consisting of floating 



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