300 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 11 



complete spire. Buttons clumsy, often slightly angulate and mostly in- 

 complete; holes mostly circular or broad oblong, not slitlike. Ventral 

 feet with end plate and elongate supporting rods with a complete or in- 

 complete series of holes around the edges. Dorsal papillae with small end 

 plate and shorter supporting rods. 



Color varying from light brown, with pale grayish white underside, 

 to almost black dorsum; tentacles dark, ventral feet usually pale with 

 darker end disk. 



Type : H ambu rg. 



Type locality : Juan Fernandez Island, Chile. 



Distribution : Known only from the type locality. 



Depth: Collected at tidemark. 



Specimens examined: Various individuals in the Museum of Com- 

 parative Zoology, Zoologisk Museum, Copenhagen, and Riksmuseet, 

 Stockholm. 



Remarks: The species appears to occupy a rather isolated position, 

 but with its reduced tables and large irregular buttons it seems to belong 

 most naturally with the Mertensiothuria leucospilota group. From the 

 size of the bushy tentacles and the numerous tube feet, one is inclined to 

 think that its mode of life is similar to that of the members of the 

 Selenkothuria lubrica group, attached to rocks in the surf zone, and 

 possibly using its tentacles for collecting a certain amount of planktonic 

 detritus ; as far as I know there are no observations on its biology. 



The species is included in this report, as it possibly may be found on 

 the shores of the mainland and even extend its range into the Panamic 

 region. 



Mertensiothuria fuscocinerea (Jaeger) 

 PI. 3, figs. 13-23 



Holothuria fusco-cinerea Jaeger, 1833, p. 22. Semper, 1868, p. 88, pi. 



27 (in color) ; pi. 30, figs. 22a-b. H. L. Clark, 1946, p. 435. 

 Holothuria curiosa Ludwig, 1875, p. 110, pi. 7, fig. 29. Panning, 1935, 



V, p. 4, text-fig. 107 (copied from Theel), complete list of 



references. 

 Holothuria pluricuriosa Deichmann, 1937, p. 166, text-fig. 1, nos. 



11-20. 



Holothuria pseudo-zacae Cherbonnier, 1951, p. 23, pi. 6, figs. 1-19, 21. 



Diagnosis: Large form, up to 30 cm long, with 20 large ventral 



tentacles and not too crowded appendages; cylindrical feet on the ven- 



trum and papillae on the dorsum. Inner anatomy not remarkable. One 



