ROIDBA "i NOKTH PACIFIC \M' MXfACENT W \l 1 iHER 



151 



individuals, being cylindrical or tapering and l>lnnt. and rather slender, or else shorter 

 and thicker, with a more or less broadened, truncate summit. This character u i 

 marked <>n the median than on the lateral portions of the abactinal area. In forms 

 with well-marked carina] plates there are usually numerous crowded Bpinea on each 

 plate. It is only H shorl Btep t" the production "f such form- as thai shown in 

 I'l,.,,, ire .'. which can be classed **■ a Bmall Bpined abaolata. A few specimens 

 from Tongas must be placed in alveoiata <>n account <>f tl . abactinal b] 

 and the presence of only one <>r two superomarginal Bpinea Th -dinary Toi 



(hostoma have from three or four to six superomarginal Bpines, of which oi 

 usually larger than the res) . 



Certain specimens in the Puget Sound region are similar t" th<' Tongase rai 

 (PI. 65, fig. l. <>r. us [aland, San '1111111 Islands 



T'/j'i locality of forma acanthoatoma. Popof Island, Shumagin Islands, Alaska. 

 aria. — The type of Verrill's aeanthostoma was taken at Popof [aland, Ala 

 and the forma is beet developed in the region between (Jnalaaka and Eodiak. In 

 southern Alaska, British Columbia, and the Puget Sound region it intergradee 

 frequently with isacanthous forms of alveoiata that it can be described as a Bmall 

 Bpined offshoot of the isacanthous varieties tolata having polyacanthid Buper- 



omarginals. 



A specimen from Departure Bay which 1ms the Bmall pointed abactinal Bpines 

 of Borne specimens of aeanthostoma, but only two Buperomarginal Bpines, in life 

 ilnrk bay color, the spines being Antwerp blue. 



ehdii- < at Mo Ofl 1 - N M. 



Typt locality of Eoasterias troachel Sound, Wash Simeahmoo), north- 



west boundary Burvey, Hr. ('. B. Eennerly. 



l> [ft Si George [aland, Pribilof [elands to Mont. Try Hay. Calif. 



[ntertidal /.<>• fathoms. 



8pt Three hundred and forty-six. 



rfiiMM nf Bvottariai trotehMi ■ 



Locality 



Unaluki... 



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 Rltki. Mvti 

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 Tonn 



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 DoumlA: 



10 



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 AltMlmtci, 1 mtrrnu 



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 itroM, IM6. 



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