THE APODOUS HOLOTHURIANS 165 



Eemarks. — No one seems to have seen this species except the describer and 

 he unfortunately has given us no figures. The tables, however, seem to be quite 

 characteristic and it is probable that the species is entirely distinct from ooUtica. 



MOLPADIA MUSCULUS. 



Plate XI. 



? Molpadia holothurioides Ciivier, 181 T, vol. iv, p. 24. 



Molpadia musculus Risso, 1826, p. 293. 



Ilaplodactyla mediterranca Grube, 1840, p. 42. 



Haplodactyla musculus Semper, 1868. 



Molpadia violacea Studer, 1876, p. 451. Calcareous particles, Theel, 18S6a, pi. ii, 

 fig. 4. 



Ankyroderma musculus Petit, 1883. 



Anl-yroderma perrieri Petit, 1883, p. 163. 



Anhyroderma liispankum Petit, 1883, p. 163. 



Trochostoma violaceum Tlieel, 1886a. 



Anl-yroderma daniclsseni Theel, 1886a. p. 39. Calcareous particles, pi. ii, fig. 6. 



Anl-yroderma musculus Ludwig, 1891(7. p. .569. Calcareous particles, pi. xxix. 



Ankyroderma danielsseni Ludwig, 1894, p. 164. Calcareous particles, pi. xvir. figs. 

 1-9. 



Anl-yroderma spinosum Ludwig, 1894, p. 171; pi. xvii, fig. 10. Calcareous particles, 

 pi. XVIII, figs. 1-12. 



Anl-yroderm.a musculus Perrier, 1903, p. 529. 



Anl-yroderma musculus Koehler and Yane_y, 1905, p. 95. 



Ankyroderma musculus acutum Koehler and Yane}-, 1905, p. 97. Calcareous par- 

 ticles, pi. XIV, figs. 4-7. 



Length. — 100-160 mm., of which the tail is 10-25 per cent; the diameter is 

 about one-fifth of the total length. 



Color. — Very variable; gray and red-brown, with more or less of a violet 

 tinge ; in old specimens the color may be very dark, the gray being entirely con- 

 cealed, while in young specimens the color may be uniformly gray^ with or with- 

 out a yellow-brown cast. 



Distribution. — Reported from the Mediterranean and North Atlantic (Lud- 

 wig, Koehler, Perrier) ; Kerguelen Islands (Studer) ; southern Chile (Theel) ; 

 Gulf of Panama, Galera Point, Cocos Island, Acapulco, and Gulf of California 

 (Ludwig); off Chile, the Galapagos Islands, and southern California; and in 

 Monterey Bay, California, 36-54 m. (Clark); seven "Siboga" stations in D. 

 E. I. (Sluiter); Andamans, Kistna, Ceylon, and Gulf of Bengal (Koehler and 

 Vaney). Apparently cosmopolitan, excepting only the Arctic and North Pacific 

 oceans. 



Remarks.— Ludwig is authority for the identity of Risso 's, Grube 's, and 

 Petit 's species, while the collections of the United States National Museum leave 

 no doubt of the identity of violaceum and danielsseni. Perrier asserts the iden- 

 tity of musculus and danielsseni, and Koehler and Vaney not only maintain the 



