750 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Genus FARRELLA Ehrenberg, 1838 



Zoaria with reptant stolons. Zooecia arising within the internodes 

 along the entire length of the stolon. No gizzard. Genotype : Lagenella 

 repens Farre, 1837. 



Farrella elongata (P. J. van Beneden), 1845 

 Plate 80, fig. 3 



Laguncula elongata van Beneden, 1845a :26. 

 Triticella tegeticula O'Donoghue, 1923:193. 



The zoaria are comprised of creeping stolons, which may in the older 

 colonies form a dense mat-like network upon the substrate. In the young 

 zoaria the zooecia are seen to arise from the creeping stolons within the 

 internodes, budding forth laterally and vertically without apparent order. 

 In the older colonies, this lack of arrangement packs the pedunculate 

 zooecia closely together. The zooecia are robust, elongate, ovoid to sub- 

 cylindrical in form, and are situated at the end of a long peduncle that 

 may attain a length of from 0.50 to 0.80 mm. The peduncle is trans- 

 versely wrinkled and gradually widens into the zooecia proper without 

 a definite joint. The overall length of the zooecia ranges from 1.16 to 

 1.35 mm, while the width varies from 0.32 to 0.39 mm. The diameter 

 of the primary stolon is about 0.03 mm. The polypide lacks a gizzard. 

 The tentacle number of 16 was determined from serial sections. 



A striking feature of this species is the morphology of the zooecial 

 aperture. The aperture deviates from the typical rounded or squared 

 form of the stolonate ctenostomes in that it is bilabiate. Close examina- 

 tion of the apertural area will reveal a pair of lip-like structures, each 

 reinforced by a thin but definite chitinous rim. These "lips" are found 

 only in the zooecia that have reached maturity. Farre, 1837:403, in his 

 work on Lagenella repens (Farre), 1837, a very closely related species, 

 considered the labiate structure to be opercula. 



Marcus, 1926:50, using Farrella repens (which according to Farre, 

 van Beneden, and Hincks, has only 12 tentacles) and experimentally 

 causing unfavorable conditions, produced the "Form" elongata and at 

 the same time reduced the tentacle number. Marcus overlooked the 

 fact that van Beneden reported 16 tentacles for Farrella elongata, the 

 same number that was found in the Pacific specimens. 



Triticella tegeticula O'Donoghue, 1923, is here suggested as a pos- 

 sible synonym of F. elongata, because of its habit of growth as well as 

 the morphology of the zooecia. Although O'Donoghue failed to mention 



