THE MOUNT DESERT REGION 323 



with the rounded ascopore at the base of the tube in front, 

 and the ovicell situated well below the top of the peristome, 

 distinguish it readily from any other in our fauna. 



Stomachetosellidae Canu and Bassler, 1917 

 EscHAROiDES Milnc-Edwards, 1836 



EscHARoiDEs ROSACEA (Busk), 1856. PL 10, fig. 1. Verrill, 

 1879, p. 149 {Escharopsis) ; Cornish, 1907, p. 78, Canso, Nova 

 Scotia.) Taken only once, at dredging station 94. The species 

 is widely distributed in northern waters, a number of places 

 in the Arctic Ocean, and south on the European coast to the 

 British Islands, but appears to be nowhere abundant. 



Zoarium erect, consisting of a short stalk with one or more 

 compressed lobate expansions, usually not more than about 

 i-inch in height, white or rosy in color. The primary aperture 

 is nearly elliptical, but this is soon covered by the secondary 

 aperture with a deep slit-like sinus, at one side of which is a 

 rounded avicularium. Ooecium hemispherical, imperforate, 

 granular. The frontal wall of the zooecium becomes very 

 thick and all primary characters are obscured. 



PosTERULA Jullien, 1905 



PosTERULA SARsi (Smitt). PL 15, fig. 4. (Whiteaves, 1901, 

 p. 102 (Escharoides), synonymy, references, and Canadian 

 records; Osburn, 1912 a, p. 286 (Escharoides), Labrador and 

 Cape Sable, Nova Scotia.) Rare, a portion of one colony 

 observed. A well-known northern species ; Greenland, Franz 

 Josef Land, northern Norway, and southward on the Ameri- 

 can coast to Mt. Desert Island. 



The zoarium is erect, foliaceous, rising from a broad en- 

 crusting base, the branches or frills bilaminar. Zooecia large, 

 rather regular, smooth and somewhat swollen in the young- 

 stage, with a marginal row of ovate pores. The primary 

 aperture is oval, without sinus or denticles, but it soon be- 

 comes covered with a secondary aperture of an elongate pyri- 

 form shape, within the deep sinus of which one or more small, 

 pointed avicularia are present. The secondary calcification 



