120 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 8 



Genus 12. ANAPERUS Troschel 



Anaperus Troschel (partim), 1846, p. 60. 



Diagnosis. — Large form with soft skin and numerous feet distributed 

 without order. Tentacles 10, the 2 ventral smaller. Anus with calcareous 

 teeth. Calcareous ring with posterior prolongations (apparently short) ; 

 retractor muscles fleshy. Spicules not numerous except in the stem of the 

 tentacles. 



Type species. — Anaperus peruviana (Lesson). 



Remarks. — ^As type species for this dubious genus Lesson's large den- 

 drochirote species from Payta, Peru, has been chosen since it is a question 

 whether Thyone briareus (Lesueur)from the western Atlantic belongs in 

 the genus; Thyone fusus (O. F. Miiller) — the type species for Thyone 

 s. str. — does definitely not belong here, and the fourth species, listed by 

 Troschel as Thyone cigaro Troschel, from Labrador, cannot be identified. 



It is furthermore doubtful whether Lesson's and Troschel's species 

 are identical. Very likely Lesson's species is a phyllophorid {Pattalus 

 mollis (Selenka)), while Troschel's species is a soft-skinned Thyone 

 which resembles T. briareus; ( Selenka actually united the 2 species after 

 having examined Troschel's material in Berlin). 



The only other soft-skinned large Thyone known from the upper end 

 of the Gulf of California is A thyone glasselli (Deichmann), which 

 possibly may occur as far south as Peru. If we discount Troschel's state- 

 ments about the color and size of his A. peruana — as they seem to be 

 borrowed from Lesson's description — the assumption is not unreasonable. 

 If re-examination of Troschel's material in Berlin should prove that that 

 is the case, the name Athyone becomes a synonym of Anaperus; in that 

 case Thyone briareus is excluded from the genus, and Troschel's species 

 must be named Anaperus glasselli (Deichmann), syn. A. peruana Tro- 

 schel, nee Holothuria peruviana Lesson. 



Another possibility is that Troschel's species is simply material of 

 Thyone briareus which has been wrongly labeled. Such errors were by no 

 means unusual in older times. 



Anaperus peruviana (Lesson) 



Holothuria peruviana Lesson, 1830, p. 124, pi. 46, fig. 1. 



Trepang peruana Jaeger, 1833, p. 25. — Brandt, 1835, p. 57. 



Anaperus peruanus Troschel, 1846, p. 61.— J. Miiller, 1854, pi. 9, fig. 9. 



