TROPICAL PACIFIC HOLOTHURIOIDEA. 145 



line and becomes entirely detached from the body-muscles, which are con- 

 tracted into a firm cylindrical mass, evisceration having previously occurred. 

 The skin around the mouth and the tentacles remain on the muscular mass. 



The specimens at hand range from twenty-eight to nearly 100 mm. in length 

 and show great diversity in the size, number and conspicuousness of the pedi- 

 cels and papillae. The pedicels in the midventral radius may be so few and 

 small, that they would readilj- escape notice but they may be fairly conspicu- 

 ous. In one specimen there is scarcely a trace of dorsal papillae and even 

 the marginal ones are indistinct, while in a slightly smaller specimen (Plate 3, 

 fig. 4) from the same station, practically the whole dorsal surface is occupied 

 by a double series of large conical papillae in each ambulacrum and a marginal 

 series on each side. 



In the larger of two specimens from station 4651, the calcareous ring is 

 well developed and resembles that of S. alexandri as described by Ludwig, while 

 in the smaller one, I fail to find any calcareous ring at aU, the condition which 

 Ludwig found in his specimens of aenigma. Even the calcareous tables show 

 some diversitj-; in a specimen from 4656, the tables are rather slender and have 

 a smooth spire wlule in another from the same station, the tables are stouter 

 and have rough spires. 



Probably many of the differences shown by preserved specimens, in form, 

 size, and appearance of pedicels and papillae are artificial, but there can be 

 little doubt that the species does show more or less diversity in nearly aU its 

 characters. There are also changes due to age which cannot be ignored. Yoimg 

 specimens have remarkably slender tables; the basal arms are very slender and 

 the spire, about twice the basal diameter, is very long, slender, and thorny. 

 Apparently with age, the spires become stouter and smoother as well as shorter, 

 and the basal arms are noticeably thicker. 



Station 4649. Eastern Tropical Pacific, 5° 17' .S., 85° 19' 30" W., 2,235 fms. Bott. temp. 35.4°. Fne. 



stky. gr. m. 

 Station 4651. Peru: west of Aguja Point, 111 miles. 2,222 fms. Bott. temp. 35.4°. Stky. fne. gj-. s., 



trace of shore-mud. 

 Station 4656. Eastern Tropical Pacific, 6° 54' 36" S., 83° 34' 18" W., 2,222 fms. Bott. temp. 35.2°. 



Fne. gn. m., mang. nod. 



Eight specimens. 



Synallactes triplax,' sp. nov. 

 Plate 4, fig. 14-17. 



Length, 60 mm.; diameter, less than 20 nun. Color, pale gray, nearly 

 white. General appearance much as m »S. aenigma but pedicels larger and 



' rpi;rXaJ= triple, in reference to the triradiate calcareous tables. 



