THE APODOUS HOLOTHURIANS 175 



entirely at a loss to find any satisfactory ground upon which they can be sep- 

 arated. Of course if the difference in tentacles were constant, it would separate 

 them easily; but I feel sure that this supposed difference is due entirely to dif- 

 ference in the amount of contraction, and the similarity of the calcareous de- 

 posits is so striking, I cannot doubt that armata is a synonym of albicans. Al- 

 though resembling the preceding species, this deep-water form is easily recog- 

 nized by the characteristic tables. As no connecting specimens are known, there 

 is no reason why it should not be given full specific rank. I feel quite sure that 

 the specimens from New Zealand are specifically distinct, and that those from 

 the Indian Ocean are either like the New Zealand form or are a third species. 



CAUDINA CHILENSIS. 



Molpadia chilensis J. Miiller, 1850, p. 139. Calcareous particles, 1854, pi. \i, fig. 



14, and pi. ix, fig. 1. 



Molpadia australis Semper, 1868, p. 233. Calcareous particles, pi. xxxix, fig. 14. 

 Molpadia coriacea Hutton, 1872, p. 17. 

 Microdactyla caudata Sluiter, 1880, p. 348; pi. vi, fig. 1. 



Caudina ransonnetii v. Marenzeller, 1881, p. 126. Calcareous particles, pi. iv, fig. 5. 

 Caudina meridionalis Bell, 1883, p. 58. Calcareous particle, pi. xv, fig. 1. 

 Caudina caudata Ludwig, 1883, p. 158. 



Caudina coriacea Theel, 1886a, p. 47. Calcareous particles, pi. in, fig. 4. 

 Caudina rugosa E. Perrier, 1904a, p. 16. Calcareous particles, 1905, pi. iv, figs. 10-12. 

 Caudina pulcJiella B. Perrier, 1905, p. 117. Calcareous particles, pi. v, figs. 14-17. 

 Caudina coriacea brevicauda E. Perrier, 1905, p. 121; fig. N in text. 



LENTH. 60-150 mm., of which the caudal appendage may be more than 

 half. 



COLOR. Milk white to yellowish brown. 



DISTRIBUTION. Eeported from Chile (J. Miiller) ; Picton Island, Chile (R. 

 Perrier) ; New Zealand (Hutton, Theel, et al.) ; Australia (Semper, Lampert) ; 

 East Indies (Sluiter); China (v. Marenzeller), and Japan (Ludwig). Appar- 

 ently the most widely ranging member of the genus, occurring throughout the 

 southern and western portions of the Pacific Ocean. 



REMARKS. The form of the body in this species is apparently quite varia- 

 ble, the caudal appendage in some specimens exceeding half the total length, 

 while in other cases it is apparently much less and correspondingly inconspicu- 

 ous; thus Miiller ('50), Semper ('68), and Lampert ('85) make no reference to 

 a caudal appendage, though the last two say the body has the usual "Haplodac- 

 tyla" form. According to Semper's figure ('68, Plate IX), this would indicate a 

 caudal appendage only about one-fourth of the length. A comparison of the 

 descriptions and of the figures of the calcareous deposits given by Miiller, v. 

 Marenzeller, and Theel leaves little doubt that they were dealing with individuals 

 of a single species, while Lampert 's comments on australis and coriacea show 

 that Semper's species is the same. Ludwig has given cogent reasons for declin- 



