146 PEOCEEDINGS OF THE NATIONAL MUSEUM vol. 72 



The colonies encrust corals, nullipores, sponges, and more rarely 

 shells. The species is more abundant in shallow waters. The rich- 

 ness of ornamentation is greater in calm waters. It is limited. to the 

 equatorial zone. 



Occurrence. — Fowey Light, 15 miles south of Miami, Fla., 40 fms. 

 Albatross Station D. 2319, north of Cuba; 23° 19' 



37" N.; 82° 20' 06" W.; 143 fms.; gray coral. 

 Albatross Station D. 2365, east of Yucatan; 22° 18' 

 00" N.; 87° 04' 00" W.; 24 fms.; white rock coral. 

 Florida, 44-71 meters (Smitt); Tortugas, 19-24 

 meters (Osburn). 

 Geographic distribution. — China Sea, Tizard K-eef, 43 meters; 

 Philippines. 

 Geologic distribution. — Pleistocene of Panama (Canu and Bassler). 



HOLOPORELLA SUBALBA new species 



Plate 25, Figures 1-6; text Figure 336 



Description. — The zoarium is lamellar, tubular, irregularly bifur- 

 cated, httle thickened, whitish. The zooecia are distinct, oriented 

 in every direction, httle erect; the frontal is smooth or somewhat 

 granular surrounded by scattered areolar pores; the pleurocyst 

 develops above the aperture to form a kind of tubular peristomie, 

 oblique, longer proximally. The aperture is semielliptic, transverse, 

 without visible cardelles. The interzooecial avicularia are irregularly 

 developed but always somewhat spatulated. The ovicell is opened 

 wide above the aperture. 



,, ^ A ^ f/^a = 0.12-0.15 mm. 



Measurements. — Aperturei , ^ , ^ ^ ^ „ 



^ Ua = 0.14-0.17 mm. 



Variations. — The tubular zoarial form is little explicable, for we 

 have not a single specimen with an alga as its substratum. Some 

 specimens encrust serpulae and are plurilamellar. 



On the colonies there are always some places where the cells are 

 more erect. The deep zooecia are visible only through their peri- 

 stomie and their peristomice. 



This species is very well characterized by its pleurocystal, smooth 

 and obhque peristomie, at the base of which there are always some 

 areolar pores. 



Biology. — The biology of the Cellepores is very difficult to under- 

 stand, for, irregularity being the rule, it is impossible to explain the 

 reason for the innumerable variations. 



Variations. — It is necessary to note some general observations. 

 The interior of the tubes is always clean and does not contain a sin- 

 gle parasite even in the waters where the larvae of the latter are 

 abundant. One of our specimens is very significant; it is juxtaposed 

 to a colony of Petraliella bisinuata, and although the interior face of 



