540 PROCEEDINGS OF THE NATIONAL MUSEUM VOL.84 



0.6 to 1 mm broad at the end; gastropores 0.3 to 0.5 mm in diameter 

 and about t^\'ice as deep; style slender; distal dactylo tomes usually 

 (but not invariably) oriented toward end of branch or sidewise toward 

 margin; male ampullae very small, inconspicuous, about the diameter 

 of a gastropore; coenosteum with a fenestrated, or spongy, rough 

 surface; internally solid, fine grained. 



Description. — The type colony is 140 mm high and 185 mm broad 

 and consists of a stout trunk (20 by 15 nam thick) and massive, 

 compressed, dichotomously divided, terminally blunt branches lying 

 in one plane so that the general form is strongly flabellate. The 

 proximal branches are 20 to 25 mm broad and about 15 mm thick. 

 The trunk is devoid of pores (though there are faint scars of old ones), 

 but all surfaces of the branches are crowded with coarse projecting 

 dactylotomes standing singly or coalesced into groups of 2 to 8 or 10. 

 On the front of the colony the scoop-shaped dactylotomes are about 

 one-third to one-half longer than on the back. 



On the proximal part of the main branches, the dactylotomes are 

 not oriented in any definite direction ; but distally the groove is usually 

 turned toward the end of the branch, or sidewise toward the margin, 

 as is indicated in the photograph. The gastropores are irregularly 

 distributed in the deep and rather narrow spaces between the dactylo- 

 tome projections; but at the base of the main branches near the trunk, 

 where the zooids are uncrowded, 2 to 7 low dactylopores may irregu- 

 larly surround a gastropore in a primitive cyclosystem. 



The gastropores are unequal in size, the diameter at mouth varying 

 from 0.3 mm to 0.5 mm, with a few as small as 0.21 mm. The majority 

 are around 0.4 mm. The depth is a little hard to determine but is 

 generally about twice the diameter at mouth. The gastrostyle is a 

 fairly sharp one, rather slender, not filling the cavity. It extends 

 rather more than halfway to orifice. The furrow of the dactylopore 

 (i. e., the dactylo tome), at the end of the projection, is about 0.5 mm 

 deep and 0.3 mm wide. Length of projection varies accordiug to 

 position; the longest are about 2 mm. The dactylostyle is a very 

 narrow, carinate cheval-de-frise of delicate, short spicules, which in 

 the longer dactylotomes extends about half the length of the furrow 

 and in the shorter ones about three-fourths. Scattered, very tiny 

 pores may represent secondary dactylopores. 



The ampullae (probably male) are inconspicuous and relatively 

 very small, being simply slight swellings at the base of the dactylopore 

 projections, the cavity subspherical with a diameter about that of a 

 larger gastropore. The wall is verv^ delicate — a fine, irregular grille. 



The coenosteum is hard and very solid, but the surface is spongy or 

 minutely fenestrated, with ii-regidar trabeculae and tiny raised irregu- 

 lar processes. After cleaning with sodium hypochlorite solution the 



