538 PROCEEDINGS OF THE NATION.VL MUSEUM vol.84 



portion of the cavity being sunken beneath the surface. They are 

 about two-thirds the diameter of those of the other specimen and are 

 probably male ampullae. 



This species resembles nanneca more than pourtalesii or zarhyncha. 

 It differs in the form of colony, color, and details of the pores. For 

 instance, the dactylopore lip is lower, the gastrostyle is more robust, 

 and the dactylotomes are arranged around the gastropore in a primi- 

 tive sort of cyclosystem. Some such organization may well have 

 preceded the specialized structure characteristic of Stylaster, Allopora, 

 and Cryptohelia. 



This species is kno\\Ti only from the Okhotsk Sea. Dr. Broch 

 records specunens also from lat. 54° 36' N., long. 143° 48' E., 165-150 

 meters. 



ERRINOPOEA NANNECA. new species 



Plate 66, Figure 1; Plate 67; Plate 69, Figures 2, 2a 



Diagnosis. — Colony dendritic, flabelliform, yellowish buff; gastro- 

 pores extremely small (0.16 to 0.2 mm in diameter), relatively deep, 

 with a slender sharp style reaching about halfway to aperture; 

 dactylotomes projecting but smaller than in pourtalesii; when dactylo- 

 pores become crowded the styliferous furrow is oriented toward end of 

 branchlet; female ampullae relatively large, blisterlike with thin wall; 

 coenosteum solid, the surface minutely roughened, microscopically 

 porous. 



Description. — The type colony is 130 mm high and 80 mm broad. 

 The three main branches %\dth their branclilets lie in the same general 

 plane, so that the colony tends to be flabellate. The main trunk 

 of the colony is 18 to 25 mm thick, slightly compressed beyond the 

 base, this compression becoming more and more pronounced until the 

 distal or top branchlets are decidedly flattened or compressed, with 

 truncate or rounded ends. Below these flattened terminal branches, 

 others are more nearly terete. Most of the zooids are on one face 

 of the colony, which may be called the front. On the back the pores 

 are found usually near the margins of the flattened branches. Even 

 the backs of the slenderer branchlets are fairly free from pores except 

 near the tips. 



On the branclilets, the furrow of the projecting dactylopore is 

 generally directed toward the end. On the main branches where they 

 are less crowded (except for abundant ampullae) the furrow may be 

 turned in any direction, depending upon the position of the asso- 

 ciated gastropore. Wliere the gastropores are scattered, as on the 

 trunk and main branches, 2 or 3 small dactylopores are associated with 

 a gastropore, but the furrow does not always face the gastropore — 

 it may in fact be turned directly away from it. 



