HOLOTHUEIANS OF NEW ZEALAND. 43 



in spiculation, and the identity in locality ; the condition of the 

 type specimen of T. longidentis being such as to preclude detailed 

 comparison in other respects. 



I regret to have to differ from the opinion of so great an 

 authority as Theel, who, while redescribing T. caudatum from 

 specimens furnished by Captain Hutton, also describes his own 

 T. rugosum as distinct ; but I cannot help thinking that there 

 has been some oversight here, and that an impartial observer 

 would admit that Theel's own descriptions are almost sufficient 

 to establish the identity of the two. 



In order to justify my conclusions I must now discuss the 

 evidence in some detail. 



The original description of Hutton's Thyone longidentis runs 

 as follows : — 



" Cylindrical ; body rugose, with numerous small suckers ; 

 head smooth, transversely striated ; tentacula five, short, thick, 

 clavate, pedunculated, frondose; dental apparatus very long, 

 nearly half the length of the body, tubular for half its length, 

 the rest cut into five teeth. 



" Brown, tenacula pale brown. 



" About an inch in length. 



" The dental apparatus is composed of five plates, each bifid 

 for half its length, joined to one another, and the lateral process 

 of the two adjacent plates together form a tooth." 



In 1879 Captain Hutton changed the name to " Pentadactyla 

 longidentis^^ erecting the new genus Pentadactyla especially for 

 the reception of this species, with the generic diagnosis — " Feet 

 evenly spread over the greater part of the body. Tentacles five, 

 pedunculated, frondose ; dental apparatus very large." He 

 also observes of the species, " It is, however, evident that it is 

 not a Thyone, but belongs to the family Aspidochirotcey Why 

 this conclusion should have been arrived at is difficult to see, for 

 the author describes the tentacles as " frondose," and I find 

 from examination of the type specimen that well-developed 

 retractor muscles are present. Theel, no doubt correctly, sup- 

 poses the species to be a Dendrochirote, though possibly not a 

 Thyone. 



Unfortunately, the type specimen (from the "Wellington 

 Museum) was represented merely by the empty skin, from which 

 all the viscera have been removed, and by the separated pharynx 

 (in the same bottle) with the calcareous ring intact (Pi. 6. fig. 62) 



