76 the apodoxis holothueians 



Opheodesoma serpentina. 



Synapia serpentina Miiller, 1850, p. 132. Calcareous ring and attachments in 



Miiller, 1854, pi. ix, fig. 5, and calcareous particles, pi. vi, fig. 16. 

 Euapta serpentina Ostergren, 1898&. 

 pheodesoma serpentina Fisher, 1907. 



Length. — 300-900 mm., with diameter 20-25 mm. 



Color. — Clear greenish gray or dusky yellowish brown, with or without 

 broad dusky bands and a few dusky blotches ; the bands are three or four times 

 as wide as the dusky lines in grisea. 



Distribution. — Reported from Zanzibar (Selenka, Lampert, Ludwig) ; Cel- 

 ebes (Miiller); Bay of Batavia, Bima, Kur, Amboina, D. E. I. (Sluiter); 

 Ternate (v. Marenzeller) ; and Pulo Edam, E. I. (Ludwig). Apparently hav- 

 ing the same distribution as godeffroyi, though it has not yet been taken west 

 of the East India Islands. 



Remarks. — Sluiter ('88) says this species is much more rare than grisea 

 in the Bay of Batavia, but is easily distinguished by the difference in color, 

 and adds that the calcareous ring is somewhat ditTerent. Later ('94) he says 

 that the only way the specimen from Amboina could be distinguished from 

 grisea was by the calcareous ring. Lampert ( '96) mentions a small specimen 

 with 17 tentacles, notes some interesting color variations, and calls attention 

 to the resemblance to grisea. It is very probable that the two species are iden- 

 tical. 



POLYPLECTANA, gen. nov. 

 (ttoAu's, many, + TrAcKTamt, feelers; in reference to the numerous tentacles.) 



Tentacles pinnate, 25, sometimes 26 or 27; individuals are often found 

 with 24 or fewer. Digits numerous, 15-40 on each side. Cartilaginous ring 

 present. Polian vessels very numerous, 20 or more. Stone-canal single. Stock 

 of anchors not branched, though finely toothed ; arms smooth, but vertex with 

 some minute knobs. Anchor-plates with large central hole, surrounded by six 

 other large holes, all dentate except the most i)Osterior, which may be smooth, 

 and with two large and several small entire holes at narrower posterior end, 

 where a well-formed and distinctly arched bow crosses outer surface of plate. 

 Miliary granules present, but tentacles without supporting rods. 



This genus is monotypic, for I am unable to find any valid character by 

 -^^iich. to A\simg\\\sh Synapta hallipeplos Sluiter ('88) from the longer and 

 better-known Synapta hefersteinii Selenka ('67). As for Fistularia tenuis 

 Quoy and Gaimard ('33), I think it very unlikely that the specimen was a 

 Synaptid at all ; certainly it is impossible to determine the point positively. 

 The following, then, must be considered the type and only known species. 



