720 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



the oral surface; in nearly all individuals, however, both young and old, the 

 terminal two or three segments (except the claw) have a dusky spot on the oral 

 side. This marking seems to be very constant in Tobagoan specimens. Occasional 

 individuals are found in which the pinnules and dorsal side of the aiins are 

 plenteously besprinkled with silvery white, giving them an exceptionally hand- 

 some appearance. 



"All of the small specimens found were brownish yellow or bright brown, 

 more or less marked and banded with purple, and this general coloration is not 

 rare in adults, particularly in those found under slabs of rock on Buccoo Reef and 

 in similar shaded places. Some of these individuals were very handsome in their 

 brilliant array of purple and gold, and it was hard to believe they were really 

 identical with the dull-colored specimens from the shallows of Buccoo Bay. A 

 natural inference from the specimens seen is that (he young are uniformly j'ellow 

 or brownish yellow, and that the purple pigment develops as they mature, in some 

 individuals completely obliterating the original color, but usually appearing simply 

 as spots, blotches, and cross bands. One could scarcely avoid the impression that 

 the development of the pigment is associated with life in the open sunlight [as 

 suggested by the present author in 1908], but there w-as no chance to secure an 

 answer to the interesting question which suggests itself: Do the bright-colored 

 individuals avoid the sun because they lack pigment, or do they lack pigment 

 because they have never lived exposed to the sun ? " 



Family CALOMETRID^. 



Neometra conarninis. — White, with yellow bands on the arms and pinnules, 

 more rarely on the cirri. 



Neometra gorgonia. — White, with purple bars and blotches on the pinnules. 



Neometra multicolor. — (a) Usually a delicate light grayish purple or lavender, 

 with narrow bands of dull yellow on the arms. The cirri are light lavender, 

 usually with a narrow band of yellow about the end of each segment. 



{h) One specimen is pure white, the arms crossed by a broad deep purple band 

 near the middle and another near the tip. 



Pectinometra ^avopurpurea. — («) Lavender, the arms crossed by bands of 

 dull yellow; lower pinnules yellow, banded at alternate articulations with purple; 

 cirri yellow. 



(6) Arms as in the preceding; centrodorsal and division series orange; cirri 

 purple. 



(c) Arms clear yellow, sometimes faintly blotched with light purple; centro- 

 dorsal and division series orange ; cirri deep purple, banded with white. 



Gephyrometra propinqua. — Reddish and purplish brown, marbled with light 

 yellow, tlie dark and the light in about equal proportions; division series and lower 

 brachials purple, with a median line of white; two or three areas of white with 

 purple spots distally on the arms. 



Gephyrometra versicolor. — Rich deep purplish brown, the basal portion of the 

 arms with a row of lateral yellow spots ; division series yellow, transversely banded 



