HYDROCORALS OF THE NORTH PACIFIC — FISHER 551 



cup, the bottom being the same for both (a, sectioned male ampulla in situ, 

 0.425 mm in diameter, showing laminated inner surface). 



2-26, Allopora norvegica pacifica: 2, A cyclosj-stem, X 30, extreme diameter 

 0.8-0.85 mm, tip of gastrostyle seen in profile owing to curvature of pore; 

 2a, X 30, slender style of specimen mentioned in text; 2b, X 30, sectioned 

 cyclosystem from male fragment with sectioned ampulla in situ (a), depth 

 of gastropore 1.2 mm, length of style 0.6 mm. 



3-36, Allopora boreopacifica: 3, Sectioned cyclosystem, X 30, showing on left a 

 sectioned dactylopore and an isolated dactylopore; 3a, portion of branchlet 

 bearing female ampullae, X 30, uppermost cyclosystem 0.74 mm in diameter; 

 36, X 30, a sectioned female ampulla from same branchlet as fig. 3a. 



Plate 54 

 1-16, Allopora caynpijleca trachystoma: 1, Type, longisection of a cyclosystem, 

 X 20; la, several female ampullae and a cyclosystem, X 20; 16, smaller 

 cyclosystem showing three outgrowths characteristic of smaller branchlets, 

 from specimen figured on pi. 46, X 20. 



2, Stylaster gemmascens alaskanus: Three ampullae, probably male (indicated by 



arrow, pi. 47, fig. 2), seen somewhat more in profile; diameter of ampulla 

 about 0.75 mm; X 20. 



3, Allopora verrilli: Cyclosystem of specimen from station 4777 figured on pi. 57, 



fig. 2, X 30; one dactylotome is imperfect. 



4, 4a, Allopora papillosa: 4, Largest cyclosystem of type specimen, X 30; 4o, 



section of a cyclosystem showing characteristic gastrostyle in style chamber, 

 X 30. 



5, 5a, Allopora petrograpta: 5, An unusually symmetrical cyclosystem showing 



large gastrostyle (some gastrostyles are smaller and some relatively larger 

 than this), X 30; 5a, sectional view showing two female ampullae and a 

 smaller cyclosystem with characteristic style, X 30. 



Plate 55 



1, Allopora norvegica pacifica: Front view, X 2, station 5016. 



2, Allopora boreopacifica: Back of colony, natural size, station 5016. 



3, Allopora venusta: Female from station 2875, front view, X 2. 



Plate 56 

 Allopora stejnegeri, type: 1, Portion of right branch of fig. 2, X 4^4; 2, major 

 portion of colony (base omitted), X 2. 



Plate 57 

 Allopora verrilli: 1, Male colony from Sucia Islands, Wash., X 3; 2, smaller of 

 two colonies from station 4777, female, X 4>^ (the back of colony has nearly 

 as many cyclosystems; in the other colony there is no differentiated front); 

 3, type specimen, X 2, somewhat beach worn. 



Plate 58 

 Allopora calif arnica: Small portion of a large colony from Monterey Bay, Calif., 

 mentioned in text; U.S.N.M. no. 43275; X 2. 



Plate 59 

 1, 2, Allopora porphyra: 1, Part of type colony, X 6; 2, another fragment of type 

 colony, X 3. 



3, Allopora papillosa: Type, X 6. 



4, Allopora petrograpta: Part of type, X 6. 



