326 . BIOLOGICAL SURVEY OF 



Escharellidae Levinsen, 1909 

 This family was established by Levinsen to include a num- 

 ber of genera of the ScMzoporella-Lepralia-Microporella sort 

 and others, some of which have later been removed to other 

 families. Canu and Bassler, in 1917, partly solved the prob- 

 lem of expressing relationships in this loosely associated fam- 

 ily by indicating four groups — Schizoporellae, Hippoporae, 

 Peristomellae, and Microporellae — ^with an addendum of 

 ^divers genera' unplaced. Later (1929) they raised these 

 groups to the dignity of subfamilies without making use of 

 the recognized subfamily ending 4nae.' Still a number of 

 genera cannot be placed definitely and must be given further 

 study before they can be allocated in the present subfamilies 

 or new groups established for them. 



Schizoporellinae Canu and Bassler, 1917 

 This subfamily is constituted chiefly of the old genus 

 ScJiisoporella, which has now been broken up into numerous 

 genera. According to the usage adopted b}^ Canu and Bass- 

 ler, Schizoporella is retained for those species which are not 

 well enough understood to be placed in other genera which 

 are better known. 



ScHizoPODRELLA Canu and Bassler, 1917 

 ScHizopoDEELLA UNICORNIS (Johustou), 1847. (Osbum, 

 1912, p. 236 (Schizoporella), for synonymy and references.) 

 Rare, one colony, without special data, encrusting a pebble. 

 The species is cosmopolitan. On the Atlantic coast of North 

 America it occurs abundantly from Cape Cod to Florida, and 

 it has been reported from Greenland waters a number of 

 times and from other places in the Arctic, so it is difficult to 

 explain why it seems to run out north of Cape Cod and why 

 it has not been recorded for eastern Canada. 



It is so well known as to scarcely need any description in 

 this place. In our specimen, the front wall is rather coarsely 

 perforated with tremopores, and the surface is irregular in 

 secondary calcification. The umbo below the zooecial aper- 



