296 J- Playfair Mc Murrich, 



stitute tlie directives. One pair of tlie directives (tlie siilcar pair) 

 corresponds to tlie Single siphonoglyph, and is perfect, wliile tlie 

 other pair (sulcular) is imperfect. The remaining- foiir pairs of tlie 

 first set have their longitudinal muscles on the endocoelic faces and 

 are situated on either side of tlie imperfect directives, the pair 

 nearest these on eacli side (siilculo-lateral) consisting- of a perfect 

 and imperfect mesentery in that order, while the next pair (sulco- 

 lateral) on either side has either a similar arrangement or eise con- 

 sists of two perfect mesenteries. The second set of niesenteries also 

 have their longitudinal muscles on the endocoelic faces and are 

 interposed between the sulco-lateral pairs of the first set and the 

 siilcar directives ; each consists of an imperfect and perfect mesentery, 

 the latter of wliich is always that nearest the siilcar directives; 

 they develope bilaterally and successively in the exocoels on either 

 side of the sulcar directives. 



Family Zoanihidae Dana, 1846. 

 With the characters of the order. 



Sub-family Macrocneminae Haddon et Shackleton, 1891. 



Zoanthidae with both members of the sulco-lateral principal pairs 

 perfect. 



Genus Epwoanthus Gray, 1867. 



Macrocneminae with the polyps arising independently from an 

 expanded or band-like coenenchyme; the coliimn wall encriisted witk 

 foreign particles; sphincter mesogioeal; no ring sinus. 



26, Mpizoanthtis 2)(^tfif/oiiic7ius Carlgren, 1899. 



No. 254. Calbuco. 20 fathoms. Several colonies. 



Some of the colonies are seated upon hydroid stems and others 

 on stones and Shells. In those upon hydroids the coenenchyme is 

 but slightly developed, some of the polyps being qiiite separate from 

 the others, but in the rest the coenenchyme forms an encrusting 

 layer covering the substratum and gives rise to a variable number 

 of polyps. These have the form of a short cylinder (Fig. 85j or of 

 a dome, the larger ones measuring from 5 — 6 mm in height, with a 



