AND ECHINOIDEA OF THE KOREAN SEAS. 



429 



studying the large collections in Paris, concurs in these views, 

 and maintains tlie consolidation of the above-mentioned forms, 

 including also A. hystrix (Val.), M. & T.* 



M. Perrier further expresses his opinion that the diflferences 

 upon which the separation has stood are nothing more than con- 

 ditions of age and locality — the series of specimens which the 

 French savant has had the opportunity of examining being pro- 

 cured from stations as widely distant as Zanzibar, Muscat, Ceylon, 

 Hong-Kong, Fiji Islands, Port Jackson and several other loca- 

 lities in Australia, thus indicating a very extensive distribution 

 of the A. polyacanthus type. 



Although the present specimen is in a somewhat weathered 

 condition, it can unmistakably be assigned to the varietal group 

 formerly described under the name of A. armatus, M. & T. In 

 each ray the three marginal plates which succeed to the inner- 

 most in the arm-angle are destitute of tubercles and dorsal mar- 

 ginal spines. This character is regular, and accords with the 

 typical description given in the * System der Asteriden.' Liitken 

 (Vidensk. Medd., 1864, p. 132) chronicles the occurrence of con- 

 siderable irregularity and variation in the number of tbese spine- 

 less plates in different rays of the same individual, and cites 

 examples from Hong-Kong having only one, or two, or even none 

 of the undeveloped spineless plates on different rays of the same 

 specimen. This starfish measures E = 35 millims., r = 9*6 millims. 



Without calling in question the accuracy of M. Perrier's de- 

 termination, the occurrence of such instances as this of a form 

 presenting strongly marked variations at different stations within 

 the area of its distribution, urges upon naturalists the necessity 

 of exercising extreme caution against being led away by a ten- 

 dency to group too comprehensively the forms which may be 

 included within a large and widely distributed genus ; for how- 

 ever seriously the multiplication of frivolous " species " may em- 

 barrass a classification, the wholesale grouping, or, in other words, 

 the unbounded extension of the limits of specific character, is 

 productive of much more injurious results, in that it curtails the 

 precision of definition, and, whilst ignoring environment as a 

 factor, divests nomenclature of one of its highest and most im- 

 portant qualities. 



* " Stellerides du Museum," Archives de Zoologie experimentale at g6n6rale 

 (Lacaze-Duthiers), tome v. 1876, p. 275. 



