526 PROCEEDINGS OF THE NATIONAL MUSEUM VOL.84 



Siicia Islands, Wash., while calif ornica has not been found north of 

 the region of the Farallone Islands, Calif. 



ALLOPORA VENUSTA Verrill 



Plate 55, Figure 3; Plate 61, Figures 2, 2a 



Allopora venusia Verrill, Trans. Connecticut Acad. Arts and Sci., vol. 1, p. 

 517, pi. 10, fig. 9, 1868. — Fisher, Ann. Mag. Nat. Hist., ser. 10, vol. 8, 

 p. 393, pi. 15, figs. 2, 2a, 1931. 



Diagnosis. — Differs from A. californica in having very short dactylo- 

 tomes and a shallower gastropore with rounded bottom; gastrostyle 

 larger, enclosed in a definite style chamber, its summit encroached 

 upon by bottom of gastropore proper. 



Description. — All the specimens of this species I have examined are 

 much smaller than those of calijornica. The type colony is 25 mm 

 high and 50 mm broad, its expanded base attached to a water-worn 

 stone. It rises in stout lobes or branches; some of the branches are 

 broad and somewhat palmate or digitate; the terminal branchlets are 

 mostly round, about 3 or 4 m^m thick, with obtusely rounded tips. 

 Several small colonies all from Cape Flattery, Wash., are about 35 

 mm high and 40 mm broad, with few dichotomous branches. The 

 Monterey colony is 70 mm high, 70 mm broad, and about 30 mm 



thick. 



The cyclosystems are subcircular, with a low, abruptly raised border, 

 and 5 to 8, usually 6 or 7, shallow subequal, dactylotomes, much 

 smaller and more nearly equal than those of calijornica. The central 

 cup is shallower and of a different form (pi. 61, fig. 2a). These dif- 

 ferences are not brought out by Verrill's diminutive figures. Viewed 

 from above, the gastrostyle tip is seen through a subcircular aperture 

 of the bottom of the cup. The border of this aperture is a ridge com- 

 posed of ornate, lobate rugosities, somewhat more prominent than the 

 fenestrated rugose skeleton of the cup itself and only clearly apparent 

 in specimens cleaned with sodium hypochlorite solution. The entire 

 breadth of the minutely hirsute style is not apparent from above. 

 Diameter of cyclosystems 0.5 to 0.8 mm. 



The ampullae are imbedded in the coenosteum and only occasion- 

 ally produce a faint swelling of the surface. The male are subspheri- 

 cal or a little higher than broad and about 0.25 to 0.4 mm in diameter. 

 The female are about 0.75 mm in diameter and conspicuously lower 

 than wide. 



A pale violet form from Cape Flattery, 40 fathoms, has usually 

 appreciably deeper cups than the type forma. The margmal dactylo- 

 pores are typical. 



A southern form (Farallone Islands and Monterey Bay, rose pink 

 in color) also has slightly deeper cups. The Monterey Bay example, 

 in addition, has an unusually small aperture in the bottom of the cup. 



