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, gray, or green ; violet does not occur with orange, black, gray, 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; artd 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 coniatulids 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. Antedon biftda. 

 Pectinometra ftavopurpurea. Antedon mediterranea. 

 Ptilometra macronema. Antedon adriatica. 



(b) Arms and pinnules uniform in color, but the ventral and dorsal surface 

 of different colors : 



Comatella nigra. Htterometra nematodon. 



Capillaster multiradiata. Amphimetra discoldea. 



Dichrometra ddderleini. 



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 : 



Comastef parvus. Lamprometra protectus. 



Comantheria briareus. Cenometra delicata. 



Comanthus 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 liitkeni. Bcdanometra elongata. 

 Comanthus solaster. Heliometra glaciali-s. 

 Comanthus parvicirra. Erythrometra ruber. 



Hathrometra prolixa. 



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

 Zygometra microdiscus, young. Neometra gorgonia. 

 Heterometra samgnii. Antedon bifida. 

 Heterometra crenulata. Antedon mediterranea. 

 Lamprometra palmata. Antedon adriatica. 

 Cyllometra albopurpurea. Dorometra mauritiana. 

 Oligometrides adeonce. Dorometra nana. 

 Tropiometra picta. Eumetra chamberlaini. 

 Gepliyrometra propinqua. Perometra diomedece. 



Hathrometra ienella. 



