178 the apodous holothurians 



Caudina pigmentosa. 

 Cnudina pigmentosa 1\. Ferrier, 1904a, p. 16. 



Length. — 125 mm., of which 55 are caudal appendage. 



Color. — Grayish red. 



Distribution. — Eeported only from Tierra del Fuego (Perrier). 



Eemarks. — This is indeed, as Perrier says, a most remarkable and interest- 

 ing species, a puzzling connecting link between Caudina and Molpadia. The 

 tentacles and caudal appendage, as well as the basis of the curious de- 

 posits, ally it with Caudina, while the red phosphatic layers of the deposits are 

 very much like Molpadia. The longitudinal muscles show a tendency to form 

 retractors where they join the calcareous ring, and most remarkable of all is the 

 presence of a bunch of Cuvier's organs similar to those which Miiller describes 

 for chilensis. It is not impossible that this is simplj' an old and abnormal (per- 

 haps diseased) specimen of chilensis, but we are not justified at present in as- 

 suming that such is the case. Were it not for the red deposits, however, it is 

 not probable that any one would question the reference of this individual to 

 chilensis. 



ACAUDINA, gen. nov. 

 (a, ]irivative, -j- raudinn: in refercnee In ilir marked iliffercnce from Caiiduia.) 



Tentacles 15, with only two small digits. Body cylindrical, stout, not hav- 

 ing a caudal portion and not even tapering posteriorly. Radial pieces of cal- 

 careous ring with very conspicuous, bifurcated, posterior prolongations. Cal- 

 careous deposits in the form of thick plates, with few, small perforations and 

 a number of conspicuous, sharp projections. Phosphatic deposits wanting. 



This genus is established for the following remarkable species, which is very 

 different in color, form, and calcareous deposits from any other member of the 

 family. Its relationships are very doubtful, though the calcareous particles seem 

 to ally it more closely with Caudina than with any other genus. 



ACAUDINA DEMISSA. 



Plate XII, Pigs. 3, 4. 



Molpadia demissa Sluiter, 1901, p. 110; pi. iii, fig. 4. Calcareous particles, pi. x, 

 fig. 11. 



Length. — 160 nam., the diameter about 45. 



Color. — Dark brown-violet, with irregularly scattered, oval clear spots, 

 caused by aggregations of the calcareous plates. 



Distribution. — Reported only from Madura Strait, northeast Java, 330 m. 

 (Sluiter). 



