TROPICAL PACIFIC HOLOTHUBIOIDEA. 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. 



Calcareous particles numerous and characteristic. In tentacles, rods few, 

 40-60 ix 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 n 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 ll 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 airoms = without trouble + xpiros = picked out, in reference to the ease with which it may be 

 distinguished from allied forms. 



