670 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Genus BIENTALOPHORA Borg, 1944 



"Zoarium erect, branching repeatedly, branches originating through 

 forking of the stem; zoarium composed of autozoids, kenozoids and 

 gonozoids. Kenozoids smaller and shorter than autozoids, always closed, 

 numerous, forming greatest part of surface of zoarium. Autozoids pro- 

 truding through layer of kenozoids, distal portions of their cystids ar- 

 ranged in quincunx or spirally, opening all around the stem. Gonozoids 

 with middle portion large, strongly dilated, traversed by numerous auto- 

 cystids; distal portion seemingly not terminal." (Borg, 1944:114). 

 Genotype Entalophora regularis MacGillivray, 1887:219. 



The two striking characters which distinguish this genus are : ( 1 ) 

 the greater development of the ovicell which extends over a capitulum 

 or broader area of the stem and surrounds some peristomes, and (2) 

 the presence of a thin layer of completely closed small kenozoids over 

 the zoarium between the peristomes. 



The nature of the ovicell, enclosing peristomes, would place the mem- 

 bers of this genus in Diaperoecia Canu, but as this character appears in 

 a number of other genera which are zoarially quite distinct, I have come 

 to the conclusion that parallel evolution may apply to the development 

 of the ovicell as well as to the zoarium. 



Bientalophora cylindrica new species 

 Plate 70, figs. 10 and 11 



The zoaria are erect, with round straight stems and branches 1.50 

 to 1.60 mm in diameter; dichotomous, the branches diverging at an 

 angle of about 60 degrees, the distance between branches about 1.50 

 cm ; in one case two branches have fused where they came in contact. 

 The branches are very slightly widened toward the tip. The bases of 

 both of our colonies are broken away, but the remaining longest portion 

 measures 17 mm in length. The general appearance is much like that 

 of a Myriozoum. 



The zooecia are distributed all around the stem, irregularly quin- 

 cuncial, their tubes not visible on the surface. The peristomes are very 

 short, the longest not more than 0.10 mm high, 0.15 to 0.17 mm in 

 diameter, the apertures 0.12 or 0.13 mm. There are frequent small areas 

 which are free from peristomes. The whole surface between the peri- 

 stomes, clear up to the growing tips, is covered by a layer of small 

 kenozooecia which are thickly perforated by small pores and their out- 

 lines marked by slightly raised lines. These kenozooecia form the 



