MONOGRAPH OF THE EXISTING CRINOIDS. 735 



Expressing the above in different form it appears from the data at hand that, 

 while white and yellow occur in all possible combinations, orange does not occur 

 with violet, black, or green; red does not occur with black; purple does not occur 

 with black, gra}', or green ; violet does not occur witli orange, black, graj', or brown ; 

 black does not occur with orange, red, purple, violet, gray, green, or brown; gray 

 does not occur with purple, violet, black, green, or brown; green does not occur 

 with purple, black, or gray; and brown does not occur with red, violet, black, 

 or gray. 



It is of course true that this apparent incompatibility of colors is partly due 

 to a lack of observations and to a misinterpretation of the colors as recorded, and 

 the list must therefore be accepted with considerable reservation. 



In particolored comatulids the distribution of the colors on the arms and pin- 

 nules falls into several well-marked types, which may be arranged as follows: 



I. Arms and pinnules uniform in color : 



(a) Arms and pinnules uniform in color, but differing in color from the cirri: 

 Lamprometra protectus. Aiitedon bifida. 

 Pecthiometra flavopurpurea. Antedon mediterranea . 

 Ptilometra macronema. Antedon adriatica. 



(b) Ai-ms and pinnules uniform in color, but the ventral and dorsal surface 

 of different colors : 



C'omatella nigra. HfMrometra nematodon. 



CapUlaster niultiradiata. Amphimetra discoidea. 



Dichrometra doderleini. 



II. Pinnules of a different color from that of the arms : 



[a) The distal portion of the pinnules (and usually also the arm tips) is of 

 a different color from that of the proximal portion and the arms : 



Comnstc/' parvtis. Lamprometra protectus. 



Comantheria briareus. Cenometra delicata. 



Com/inthus parvicirra. Oligometrides adeonce. 



Zygometra punctata. Pterometra venusta. 

 Parametra orion. 



(b) All of the pinnules are of a color different from that of the arms: 

 Comissa lutkeni. Balanometra elongata. 

 Comanthus solaster. IleUometra glacialis. 

 Comanthus parvicirra. Erythrometra ruber. 



B athrometra prolixa. 



III. Arms and pinnules irregularly spotted, mottled, and blotched: 

 Zygometra 7nicrodiscus, young. Neortietra gorgonia. 

 Heterometra savignii. Antedon bifida. 

 Heterometra crenulata. Antedon mediteii'anea. 

 Lamprometra palmata. Antedon adi^atica. 

 Cyllometra alhopurpurea. Dorometra mauritiana. 

 Oligometindes adeonce. Dorometra nana. 

 Tropiometra picta. Eumetra chamherlaini. 

 Gephyrometra propinqua. Perometra diomedece. 



H athrometra tenella. 



