18 McMURRICH 



From Ixalactis and Pseudophellia It is readily separated by the 

 simplicity of the tentacles and by the absence of an epidermal 

 covering to the column wall. 



2. Cribrina clegantissiina (Brandt) 



SynonyDis. — Actinia (Taractostephanus) elegantissima, Brandt. 

 ? Urticina crassicornis, Verrill. 



The identification of the species here described with Brandt's 

 A. clegantissiina is necessarily somewhat uncertain, since the 

 original description is not as complete as could be wished. So 

 far as the description goes, however, the agreement is sufficiently 

 close to warrant the identification. 



Habitat. — '* A very common form on the rocks and piles " in 

 Puget Sound. (Calkins.) 



External form. — The base is circular and adherent. The 

 column is almost cylindrical (Figs. 7 and 8) and in its upper 

 part is provided with vertical rows of verrucas, which become 

 obsolete towards the base. Some of the rows extend much 

 farther down the column than others, and according to their 

 length, about four sets can be distinguished, of which the third 

 and fourth sets are much shorter than the other two. The 

 lower part of the column is ridged transversely probably as the 

 result of contraction. A well-defined margin is present, and a 

 distinct interval exists between it and the bases of the outermost 

 tentacles. 



These are short, rather blunt at the apex and all finely ridged 

 longitudinally. They appear to be arranged in about five cycles, 

 though their total number does not agree with what would be 

 expected from such an arrangement ; as will be seen later there 

 are irregularities in the arrangement of the mesenteries which 

 probably explain the irregularities of the tentacles. The disk 

 is marked by fine radiating furrows and is slightly concave, the 

 peristome being prominent. In two of the specimens the stom- 

 atoda^um is somewhat evaginated and it can be seen that its 

 walls are longitudinally ridged. Two siphonoglyphes seem to 

 be present as a rule, though sometimes irregular in position, 

 and in one individual there were three, and in another only one. 



