TROPICAL PACIFIC HOLOTHURIOIDEA. 125 
Station 4666. Eastern Tropical Pacific, 11° 55’ 30’’ S., 84° 20’ 18” W., 2,600 fms. Bott. temp. 34.9°. 
Lt. gy. oz. 
Sixteen specimens. 
Chiridota aponocrita,' sp. nov. 
Plate 4, fig. 1, 2. 
Length in life, apparently about 75 mm.; the two fragments of the holo- 
type measure in their preserved condition, 20 X 5 mm. and 15 X 4 mm. but 
these seem to constitute only about half the animal. Color (preserved), creamy 
white. The anterior piece bears twelve tentacles, each with seven digits on a 
side; tentacles 2-3 mm. long; terminal digits a full millimeter. Calcareous 
ring narrow, with no conspicuous projections on either margin; tentacle-bases 
relatively large, nearly concealing calcareous ring. 
Calecareous particles numerous and characteristic. In tentacles, rods few, 
40-60 » long (Plate 4, fig. 1) very slightly branched at one or both ends, very 
little curved. Wheel-papillae numerous in all interambulacra anteriorly but 
few and scattered in ventral interambulacra at middle of body and perhaps 
posteriorly too; the absence of an indubitable posterior end prevents a positive 
decision. Wheels numerous in each papilla, and of diverse sizes, ranging from 
55 to 110 » in diameter. Body-wall everywhere, even in skin overlying wheel- 
papillae, crowded with minute curved rods or doughnut-shaped particles (Plate 4, 
fig. 2) only 12-20 u long. No calcareous particles in longitudinal muscles. 
Panama: Perico Island. 
Three fragmentary specimens. 
This Chiridota, although superficially not unlike several of the smaller 
members of the genus, is easily distinguished by the uniform coat of miliary 
particles in the outer layer of the body-wall. These are so numerous and small 
and have such a characteristic form, that aponocrita is one of the most easily 
recognized members of the genus. It is apparently a littoral species and no 
doubt occurs elsewhere at Panama, than at Perico Island. 
Chiridota rigida. 
Semper, 1868. Holothurien, p. 18. 
There are two headless specimens in the 1904-1905 collection, measuring 
25-30 mm. long by 4-5 mm. in diameter, which seem to be this species, though 
of course they are not certainly identifiable. They are of special interest because 
1 @rovos = without trouble + xplros = picked out, in reference to the ease with which it may be 
distinguished from allied forms. 
