A MONOGRAPH OF THE EXISTING CRINOIDS 29 



, ,T}i 1 (White. 

 + [Blue = „ 



I. YeUow (Green. 



+ [Black] = Brown. 



r , mi 1 [Purple; maroon. 

 + Blue = ,,. ; ^ 



II. Red I Violet. 



[ + [Black] = Crimson. 



No species is Itnown which exhibits a perfect blending of these two basic types 

 or their derivatives, though there are many mosaics in which both are found side 

 by side, either in different individuals or, more commonly, in the form of a color 

 pattern made up partly from one base and partly from the other, each being clearly 

 defined, in the same individual. 



It is stated that the data seem to show that the smaller stalked forms are inva- 

 riably and unchangeably yellow, which color may be, as in the case of the parrots 

 among birds, equivalent to a lack of color. Black is added to the basic color of 

 comatulids at all depths and appears to denote age. Blue is added apparently only 

 within 200 fathoms of the surface, and increases in intensity to the surface. The 

 mosaics are all httoral or shallow water types. 



Species growing among coral or on white bottom in shallow water are very dark 

 in color, often nearly black or sharply black and white, while the same species on 

 mud may be light yellow and pinkish. Thus there seems to be a close connection 

 between color and amount of illumination, the blue factor in the coloration increasing 

 with the Ught. 



There appears to be no direct relation between the color of crinoids and their 

 environment. The yellow deep water species are very conspicuous in the mud from 

 a deep dredge haul, while the color of shallow water species is commonly in great 

 contrast to their surroundings. 



It is suggested that the other echinoderms appear to be in general subject to 

 the same laws of color change as the crinoids. 



Through the kindness and courtesy of Dr. Th. Mortensen, the large and exceed- 

 ingly interesting collection of the Zoological Museum of Copenhagen had been sent 

 to me. Aside from its great intrinsic and historical value the collection was of the 

 greatest importance to me for the reason that it contamed representatives of many 

 of the Indo-Pacific types which previously I had only known through often quite 

 inadequate descriptions and figures. 



On December 10 a prehminary paper was published, including descriptions of 

 the new species in this collection. These were: 



Comanthus intricata (Lutken,MS.). Himerometra ensifer. 



Comanthus decameros. Cyllometra anomala. 



Himerometra grandis. Oligometra pulchella. 



Himerometra molleri (Lutken, MS.). Oligometra imbricata. 



Himerometra schlegelii (Lutken, Asterometra lepida. 



MS.). Mastigometra flagellifera (Lutken, 

 Himerometra producta. MS.). 



Heliometra glacialis biarticulata . 



