JAPANESE ASTEROIDEA. 153 



Sladen, in liis paper of 1879, makes some critical remarks of importance 

 on tliis species. In the following I omit the list of synonyms given [Sladen, 

 79, p. 429]. 



" Astropeden j)oli/acanthus (of armcitus-iypo) M. and T. 



"Coll. St. Jolm: Yedo Bay. 



" So far back as 1864, Dr. Lütken raised the question as to the vahdity 

 of the separation of A. armatus, M. and T., from Japan, and A. vappa, 

 M. and T., from Australia, as species distinct from the tyjpical form of A. 

 polyacantJms from the Red Sea, asserting his inability to detect in the 

 material he had examined any characters of specific value to warrant such a 

 division. M. Peeeiee, after studying the large collections in Paris, concurs 

 in these views, and maintains the consohdation of the above-mentioned 

 forms,^^ including also A. Jiystrix (Yah), M. and T. 



" M. Peeeiee further expresses his opinion that the differences upon 

 wliich the separation has stood are nothing more than conditions of age and 

 locahty — the series of s^^ecimens which the French savant has had the 

 opportunity of examining being procured from stations as widely distant as 

 Zanzibar, Muscat, Ceylon, Hong-Kong, Fiji Islands, Port Jackson and several 

 other locahties in Australia, thus indicating a very extensive distribution of 

 the A. polyacanihus 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. and T. In each ray the three marginal 

 plates which succeed to the innermost in the arm-angle are destitute of 

 tubercles and dorsal marginal spines. This character is regular, and accords 

 with the typical description given in the System der Ästenden. Lütken 

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

 iiTegularity and variation in the number of these spineless 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. Tliis starfish measm-es E, = 35 milHms., r=9.6 

 miUims. 



T.) Astrop. polyManthus, hijstrix, armatus, vappa. 



