296 BIOLOGICAL SURVEY OF 



of varying degrees of development. No spines were ob- 

 served. Harmer, 1915, ''Polyzoa of the Siboga Expedition," 

 part 1, p. 27, gives a very full synonymy and discussion of 

 the species. 



It is widely distributed in northern seas, Spitzbergen, and 

 Greenland, southward to the coast of France. The present 

 record is the farthest south the species has been noted in 

 American waters. 



Subclass GYMNOLAEMATA 

 Order CYCLOSTOMATA Busk, 1852 



Crisiidae Johnston, 1847 

 Crista Lamouroux, 1812 



Crisia eburnea (Linnaeus), 1758. PI. 1, figs. 3, 4; pi. 4, 

 fig. 3. (Osburn, 1912, p. 215, for records and references; 

 Whiteaves, 1901, p. 109, for Canadian records.) This com- 

 mon and well-known species is abundant, and was taken at 

 twenty stations. Its distribution is cosmopolitan. On the 

 eastern coast of North America it has been noted from Green- 

 land to the Chesapeake Bay. 



It is very difficult to distinguish the species of this genus 

 except by the characters of the ooecium, and many of the 

 earlier records are questionable. The growth habit of 

 C. eburnea is different from that of the following species, 

 being more sprawling and the branches noticeably incurved. 



Crisia cribraria Stimpson, 1853. PI. 1, figs. 1, 2, 10; pi. 

 4, fig. 2. (Osburn, 1912, p. 215, for references, synonymy, 

 occurrences, and description.) Common at all depths which 

 afford proper attachment, on shells, bryozoan stems, etc., and 

 often associated with C. eburnea. It has a stiffer habit of 

 growth than eburnea, from which it may be positively sepa- 

 rated by the ooeciostome which is transversely elongated 

 and flared outward, while that of eburnea is slightly sinuated 

 on the anterior border and not at all flaring. 



Apparently this is a species of American waters in the 

 north Atlantic. At any rate, it is at present known only from 

 Cape Cod to Cape Sable, Nova Scotia. 



