200 ROBERT PAYNE BIGELOW ON 



markings of the umbrella. There is a similar stripe on the dorsal side of each of the 

 larger branches which may, or may not, be continuous with the stripe on the main stem. 

 The bases of the oral funnels are of a delicate blue color, which often extends to the 

 brachial canal. The margin of each funnel is a deep brown, that shades off over the 

 blue ; while the small tentacles, or digitella, that spring from this margin are pure white. 

 The larger tongue-shaped vesicles on the arms and oral disc have a greenish yellow color 

 with a bluish green longitudinal stripe. The smaller vesicles on the arms are colored in 

 a similar way and are inconspicuous, but the cluster of very small vesicles that occupy the 

 greater part of the oral disc has a very different appearance, being lightly tinted by line 

 reddish brown pigment spots. 



The two specimens that I have called variety C, are somewhat differently colored. 

 The markings are yellowish white. The circular white band is indistinct. The rhopalial 

 bands are interrupted at the margin of the concavity of the exumbrella, and stop short 

 about half a centimeter from the rhopalial hood. At the margin of the umbrella there is 

 a white spot on each rhopalial lobe and a strap-shaped spot on each velar lobe. The 

 centre of the umbrella is whitish and opaque, so that the stomach does not show through. 

 The oral arms are translucent, milky white tinged with brown, and without distinct white 

 markings, except on the dorsal side of the principal branches. The large oral vesicles 

 are yellow and greenish yellow, with a brown centre. 



Size. The diameter of the largest specimen found is 24 cm., while the smallest 

 specimen that contained eggs measured 6.5 cm. The average diameter of twenty-three 

 adult specimens was 13.7 cm. The relative sizes of the parts are exhibited in the follow- 

 ing tables. Table 1 shows what may be regarded as the normal proportion for the species, 

 though, to be sure, some of the measurements were made only on Port Royal specimens. 

 Some of the dimensions were measured on a smaller number of specimens, and for these 

 the average diameter of the umbrella of the specimens on which these measurements 

 were made is given separately to show the correct proportions. Table 2 furnishes a 

 means of comparing the proportions in the three varieties. 



