ALASKAN HYDROCORALLIN^. 115 



gastropores average 0.25""". apart, but are rather irregular and 

 occasionally sporadic, a rounded, rather smooth-topped style fills 

 the pore nearly to the brim ; the dactylopores are arranged alter- 

 nately on opposite sides of the row of gastropores opposite the 

 intervals between the latter, though sometimes crowded out of 

 regularity ; they are furnished with subtubular projections, squarely 

 truncated at the top and open toward the gastropores, rising above 

 the general surface to about 0.5"". or more ; when perfect the styles 

 rise nearly to the summit of the enclosing hood, slender, pointed, 

 and rather feathery ; two-thirds of their length, in general, is above 

 the surface, and the depth of the gastropores is seldom greater (as 

 a rule less) than that of the submerged portion of the others. Am- 

 pullae on the surface, barely covered by a net-work of coenosteal 

 granules, which are often broken away, leaving shallow open cups 

 between the projecting hoods ; there are no scales, and the circular 

 margin of the gastropores is smooth and simple. 



Soft parts unknown. 



Habitat: in 50-100 fathoms about the Farallones Islands, off the 

 coast of California, on stones which are frequently brought up on 

 the fishermen's hooks entangled in the corals. A large stone with 

 several specimens upon it was obtained by Count Pourtales in 1873, 

 and is now in the Museum of Comparative Zoology, at Cambridge, 

 from which the specimen described was selected; other specimens 

 are in the collection of the California Academy of Sciences. This 

 coral, as well as AUopora venusta and A. californica Verrill, meet 

 with a ready sale in San Francisco, owing to their beautiful color, 

 which, however, is not lasting if the specimens be much exposed 

 to the light. The present species seems to do a good deal toward 

 bridging the gap between Errina and Distichopora, as defined by 

 Moseley. Museum number, 6853. 



I may add, in conclusion, that through the kind co-operation of 

 Prof. G. O. Sars and Miss Birgithe Esmark, I have been enabled 

 to compare the Alaskan and Norwegian Alloporas, which, however, 

 do not present any very marked points of resemblance outside of 

 the generic characters. 



