NO. 2 DEICHMANN : HOLOTHURIOIDEA ; PART II, ASPIDOCHIROTA 295 



Depth : Shallow water, concealed under rocks or in sand. 



Specimens exarjiined: The type and several specimens in the Mus- 

 eum of Comparative Zoology, and in other collections. Fourteen speci- 

 mens collected by the Hancock expeditions from seven stations, ranging 

 from Colombia to Las Tres Marias, Magdalena Island, Mexico (about 

 21° N). 



Remarks: That this well characterized and wide ranging species 

 is not a permanent element in the Panamic region is indicated by the 

 comparatively few records and by the small size of the material, 1 to 8 

 cm. It probably does not reach maturity in this area. 



The coloring in this species is a most reliable character, except in 

 cases of the youngest individuals, 1 to 3 cm long, which may be almost 

 uniformly brown; but the spicules are characteristic enough to separate 

 them from similar age groups of B. impatiens and B. arenicola. 



"Holothuria patagonicus" Perrier, well figured in his paper of 1905, 

 lacks spicules completely and is undoubtedly a mislabelled specimen in 

 which the spicules have been accidentally dissolved. It has never been 

 taken since the type was described and must be withdrawn as a synonym 

 of Brand to thuria gyrifer. 



4. Lessonothuria n. gen. 

 (Holothuria pardalis group) 



Diagnosis: Small (10 to 12 cm) spindle-shaped forms resembling 

 Brandtothuria arenicola, with small terminal tentacles and few feet or 

 papilliform feet in indistinct rows. 



Spicules stout tables with disk round, edge smooth to dentate, often 

 incomplete; spire low with 8 to 12 teeth, often reduced. Buttons in 

 inner layer, numerous, often distinctly in heaps, varying from regular, 

 with 6 to 8 holes, to incomplete, often twisted forms, occasionally with 

 one or two knobs. Feet with end plate, smaller in the dorsal ones, and 

 straight to curved supporting rods with few holes in the expanded ends 

 or transformed into elongate buttons. 



Type species: Holothuria pardalis Selenka. 



Remarks: To this group has been referred only one species which 

 is extremely variable but in which, as all authors seem to agree, the 

 numerous variations cannot be separated. In Panning's revision, the 

 species is placed, with a large number of others, in Group B, ser. 8 (V, 

 p. 3 ) . However, some of the species in this group are synonymous, some 

 belong in other groups, and the few remaining forms, incompletely 

 known as they are, have no close affinities with Lessonothuria pardalis. 



