CLARK: JAPANESE AND EAST INDIAN ECHINODERMS. 283 



the east, has satisfied me that it is futile to attempt to separate L. multifora from 

 laevigata by any constant characters, although typical examples of the two forms 

 are so easily distinguished. Specimens under 75 mm. in diameter usually show 

 the characters of multifora, but in fully grown specimens all intergradations occur 

 between the broad-rayed laevigata and the slender-rayed multifora. Unfortu- 

 nately the number of madreporites is worthless as a character, for broad-rayed 

 specimens occasionally have two, while slender- rayed specimens very often have 

 only one. Most specimens from the western part of the Indo-Pacific region seem 

 to have the rays long and slender, while most of those from Australia and the 

 Pacific Islands have the rays short and broad, but this is far from being invariably 

 true. On the whole I think we may retain multifora only as a form or variety of 

 laevigata. The specimens in the Barbour collection showed a most extraordinary 

 change in color when washed with alcohol. A few were placed in a jar of alcohol, 

 which had been previously used, and their blue tints immediately became vivid 

 orange-red. Thinking the change might be caused by impurities in the alcohol, 

 further experiments were made, which showed that the effect is produced by the 

 alcohol itself, and the mere application of perfectly pure alcohol for a few seconds 

 is sufficient to change a bright blue color to bright orange-red. Subsequent 

 application of an alkali had no visible effect. Continued immersion in alcohol 

 results in the gradual loss of red, the specimens becoming brownish-yellow. On 

 drying, the red specimens seem to retain the color quite well. In the lot of speci- 

 mens from Amboina there are now to be seen brownish-blue, blue, orange-red, 

 reddish-yellow, and brownish-yellow individuals. These facts emphasize the rule 

 that little importance can be attached to differences in color shown by museum 

 specimens of starfish. — One of the specimens from Amboina and one of those 

 from Manokwari, each bore a specimen of the peculiar gasteropod, Thyca pellu- 

 cida, described by Kiikenthal in 1897 as found by him on specimens of Linckia 

 at Ternate (see his " Parasitische Schnecken," Abh. Senck. Nat. Ges., 24 (1), 

 p. 7 ; Plate 2, figs. 7-9). 



Nardoa tuberculata. 

 Gray, 1840. Ann. Mag. Nat. Hist., 6, p. 287. 



5 specimens, 130-215 mm. in diameter. Sorong, New Guinea. Barbour 

 collection. 



These specimens were found on sandy patches among the reefs and in life were 

 a fawn-brown, which in dried specimens has become deep tawny brown, more or 

 less blotched with blackish abactinally on the rays. They agree with de LorioPs 

 (1393) specimens from Amboina in the entire absence of the dusky cross-bands 

 on the rays shown in Herklot's (1868) figure. One of the specimens has only a 

 very few of the characteristic tubercles developed. 



Pteraster obesus, sp. nov. 



Rays 5. R = 22 mm., r = 16 mm., R = 1.4 r. Breadth of ray at base, 16 

 mm. Interbrachial arcs shallow. Disc high, vertical diameter, 16 mm. ; rays 



