THE BRYOZOA 



225 



As compared with specimens from Northumberland, England, those 

 from the Pacific Coast are stouter and more vigorous. By measure- 

 ment the internodes are found to be shorter and slightly wider. Thus, 

 in the Yakutat form the average length of an internode consisting of 

 three zoecia is 42 mm., its width from tip to tip of the avicularia 

 33 mm. ; in the English form the length of an internode is 52 mm., 

 its width 28 mm. 



MENIPEA TERNATA Ellis & Solander. 

 B. forma gracilis SMITT ('67), pi. xvi, figs. 16-24. 



Habitat. In considerable quantity on the rocks at low tide. 



Local distribution. Orca, Prince William Sound. This elon- 

 gated form of Menipea ternata is also reported from Cumshewa 

 Harbor, Queen Charlotte Islands. 



Foreign distribution. Spitzbergen at 200 fms. ; Franklin- Pierce 

 Bay ; Barents Sea. 



The zoecia of this species are very much elongated, and internodes 

 consisting of three zoecia range from 60 to 90 mm. in length. Many 

 internodes, however, consist of five or seven zoecia, and it is upon 

 these that the oecia seem to occur. The avicularia, both lateral and 

 frontal, may be present or absent. In many instances in which an 

 internode consists of more than three zoecia, a frontal avicularium 

 appears below the aperture of each. In such cases, lateral avicularia 

 are sparingly developed. One may be found on the lower zoecia, but 

 not, as a rule, upon all. When oecia occur, they fill that portion of 

 the next upper zoecium which is below the aperture, and the frontal 

 avicularia occupy a narrow space between the oecium and the edge of 

 the aperture. In some cases they seem to be sessile upon the oecia. 



MENIPEA ERECTA sp. nov. 

 (PI. XIX, figs, i, 2.) 



Habitat. On an ascidian. 



Local distribution. Sitka, Alaska, 10 fms. 



Zoarium dichotomously branched, internodes usually consisting of 

 5 to 7 zoecia. Zoecia biserial, alternate, narrowed below; aperture 

 (fig. i, a/.) broadly ovate, occupying two-thirds of the front; margin 

 (/.) raised, crenulate, with two blunt spines (^.) on the upper 

 outer angle; operculum (<?/.) a flattened spine; sometimes growing 

 broad, when it is frequently more or less bifid. Lateral avicularia 

 wanting; frontal avicularia (_/". a.) few. CEcia (<#.) large, globose, 



