244 



BULLETIN 76, UNITED STATES NATION.VL MUSEUM. 



The ani are only visible in live animals. In 68 specimens 16 had one, 48 had two, 3 had three, 1 had 

 four ani. 



There may be some connection, as has been suggested, between madreporites and breaking plane, 

 but I have failed to find anything satisfactory on tlie subject. Sometimes the largest ray, or a large ray, 

 is between two madreporic bodies. In 132 specimens 87 long arms and 45 short arms were between 

 madreporites. 



I have also found this year (August, 1904) that a Phalarki ma,\ have two mouths. 



Type-locality. — "West coast of Colombia" (Gray). 



Distribution. — California (Santa Catalina and San Clemente Islands, San 

 Pedro, San Diego) and Lower California (La Paz) ; Colombia, west coast (Gray) ; 

 Galapagos Islands (California Academy of Sciences coll.). 



Specimens examined. — Forty-one from the following localities: 



Specimens of Linckia columbix examined. 



Remarks. — Two questions are suggested: (1) Is this form really distinct from 

 lAncTcia guiMingii of the Atlantic and L. pacifica of the Pacific? (2) If distinct, 

 is the name chosen the correct one ? 



I may sa}^ at the outset, that with the limited material at my disposal, and from 

 an examination of specimens in the Museum of Comparative Zoology, I am unable to 

 find any wevj satisfactory differences between L. guUdingii, L. pacifica, and L. diplax. 

 Tius opinion is also held by Dr. H. L. Clark. The three forms have been differ- 

 entiated on the basis of the most variable characters, namely, length of ray and 

 number of madreporic bodies. Perrier says (Revision, p. 143) the only characters 

 which seem to him, after an examination of numerous specimens, to distinguish 

 diplax from pacifica are: smaller size, slenderer arms, of a number varying from 

 four to seven, and the existence of two madreporic bodies. He says further (p. 147) 

 that he is unable to find any distinctive character between LlncTcia guildingii (from 

 the Atlantic) and a specimen collected at Tahiti. All writers (including myself, 

 1906) have placed faith upon the number of madreporic bodies, whereas in the present 

 group of species it is worthless for classificatory purposes, as also I think are the 

 proportions and number of rays. 



We have to deal in the present connection only with Linckia guildingii. It 

 may be assumed that the same characters hold good for ^'diplax.'' They do for 

 two specimens of very different size in the Stanford Collection. One is young, the 

 other full grown. The following differences hold good for all the specimens I have 



