NO. 2 DEICHMANN : HOLOTHURIOIDEA ; PART II, ASPIDOCHIROTA 287 



from the widespread type species described from Hawaii, which has 

 rather stout tables with long spines on the tip of the low spire, and in 

 addition a few deformed buttons. Both the type species and the present 

 form appear to be rather rare, and one has the impression that the genus 

 is a survival of a primitive, synallactidlike type which has been able to 

 hold its own in some parts of the tropical shore region. 



2. MIcrothele Brandt 1835 



Microthele Brandt, 1835, p. 54. Panning, 1929, I, p. 130 (partim). 

 Miilleria auct. {partim). 

 Actinopyga auct. {partim). 



Diagnosis: Medium-sized to large forms, with 20 large ventral 

 tentacles and numerous cylindrical feet on the ventral side, the dorsal 

 side with scattered low papillae, often placed on low warts. Anus ter- 

 minal with calcified papillae; with the skin scraped off, these papillae 

 simulate anal teeth. Cuvierian organs large. 



Spicules an external layer of crowded tables with well developed 

 disk having a varying number of holes and round to squarish in outline; 

 spire low, squat, with a single crossbeam and many short spines on the 

 top. An inner layer of large thin buttons, oval or slightly S-shaped, with 

 two rows of comparatively small holes. Ventral feet with large end 

 plate and large plates, more or less symmetrically developed with nu- 

 merous holes; dorsal appendages with reduced end plate or none, and 

 more simple rods. 



Color varying shades of brown, in one form with the papillae sur- 

 rounded by a pale area. A green fluorescent pigment present in one 

 species {M. parvula), possibly in all. 



Type species: Holothuria sanctori delle Chiaje. 



Remarks: The name Microthele is accepted in the sense in which 

 Panning used it in 1929, pp. 130-138, with some corrections, in order 

 to avoid an endless reshuffling of names. Brandt's diagnosis, 1835, p. 54 

 "Dorsi pedes parum evoluti, rarius ex eminentiis mamillosis parum 

 distinctis prominentes," fits the members of the Holothuria difficilis 

 group — as well as many others. 



Of the nine species which Panning lists, Holothuria {Microthele) 

 nobilis (Selenka) (and Holothuria whitmaei Bell) must be transferred 

 to another genus; Holothuria (Microthele) aegyptiana (Heifer) was 

 based on a poorly developed individual of the rigida group. Holothuria 

 (Microthele) lubrica (Sluiter), based on two specimens 4.2 cm long. 



