[235]

Fauna Arctica (Roemer and Schaudinn), i. 1900, p. 84; and Sitzb. Akad. Berlin, 1899, p. 98.

[236]

Sollas, Quart. Journ. Geol. Soc. 1880, p. 362.

[237]

Quart. Journ. Geol. Soc. xl. 1884, p. 795.

[238]

"Monograph British Fossil Sponges," Palaeont. Soc. xl. and xli. 1887 and 1888.

[239]

Sollas, Challenger Monograph, xxv. 1888.