238 BULLETIN 82, UNITED STATES NATIONAL, MUSEUM. 



are separated by a space much less than their own width. This condition appears 

 to be very unusual in this species. 



There are no spicules in the tentacles. 



Zygometra elegans. Examination of two specimens showed no deposits in the 

 perisome of the pinnules. 



No spicules were found in the tentacles. 



Zygometra comata (fig. 779, p. 366). The lateral perisome of the pinnules 

 between the sacculi and the borders of the lappets contains long needle-like spicules, 

 most of which lie at right angles to the pinnulars. 



There are a very few fine spicules in the tentacles. 



Eudiocrinus indivisus. Just beyond the sacculi are numerous long and curved, 

 sometimes branched, spicules running into the lappets, which lie at right angles 

 to the pinnulars. 



The genital organs are completely protected by large, thin, filmy, and delicate 

 plates. 



The outer side of the tentacles contains a rather broad band of interlaced 

 spicules which runs nearly to their tips. 



The perisomic and tentacular spicules in this species are unusually conspicuous. 



Eudiocrimus junceus (fig. 788, p. 366). Each ambulacral lappet contains 

 usually two similar smooth spicules, an outer and an inner, the adjoining ends 

 of which overlap more or less. Each is bent at an obtuse angle in the middle. 

 The outer may be branched or forked at the outer end or may be replaced by 

 two or three small straight spicules irregularly arranged. 



Each tentacle contains at the base a double (distal and proximal) continuous 

 row of small spicules, which soon coalesce, forming a single row, which, becoming 

 gradually narrower, is continued almost to the tip. When the tentacle is con- 

 tracted this row of spicules may be more or less zigzag. These tentacular spicules 

 are much the most conspicuous of all the deposits. 



Eudiocrinus pinnatus (fig. 787, p. 366). The conditions in this species are 

 essentially the same as in E. junceus. 



Eudiocrinus venustulus. This species does not differ essentially from the two 

 preceding. 



Catoptometra magnified. There appear to be no calcareous deposits in the 

 perisome of the pinnules. 



No spicules were detected in the tentacles. 



Catoptometra rubroflava. There are no calcareous deposits in the perisome 

 of the pinnules. 



There appear to be no spicules in the tentacles. 



Catoptometra hartlaubi. The lateral perisome of the pinnules contains numer- 

 ous subequal long spicules, usually straight or slightly curved, sometimes branched, 

 rarely including one or two meshes, which run from the ambulacral lappets 

 nearly to the pinnulars. Over the genital glands these spicules become shorter 

 and are practically confined to the ambulacral lappets. 



There are a few slender spicules in the tentacles which may form a continuous 

 row for some distance along the outer side. 



