HOLOTHURIOIDEA 369 



Peniagone Tlieel. (Fig. 219.) 



Body more or less elongate, the anterior end often more or 

 less neck-like prolongated. Tentacles 10 ; lateral tube-feet not 

 united by a web, except sometimes a few at the posterior end. 

 Dorsal papillae only at anterior end of body, forming a raised 

 fan-like prominence, a "veil". Calcareous deposits mainly 

 4-armed bodies with (1 to) 4 outwardly directed processes 

 (Fig. 217, 7). 



Seven species of this genus are known from the N.E. Atlantic, 

 viz. P. azorica v. MarenzeUer, from the Bay of Biscay and off 

 the Azores, 2870-4020 m. (" Hirondelle ", " Princesse Alice", 

 " Michael Sars ") ; P. ferruginea Grieg, 

 known only from 28"^ 54' N., 24° 14' W., 

 2800 - 3000 m. (only one specimen, 

 "Michael Sars ") ; P.foliacea (Herouard) 

 (Syn. Kolga foliacea Her.), from 37° 16' 

 N., 22° 32' W., 4275 m. (only one speci- 

 men, " Princesse Alice ") ; P. obsoleta 

 (Herouard) (Syn. Kolga obsoleta Her.), 

 from off the Azores, 4360 m. (" Princesse 

 Alice ") ; P. porcellus R. Perrier, from 



42° 19' N., 25° 36' W., 4060 m. (" Talis- Fig. 219.-P eniagone 



man"); P. vexillum B,. VeTiier, together WyvilUi; side view. 



• ,1,1 I- • 1 ^ Somewhat reduced. 



With the precedmg species; only one (After Grieg, "MicAae/ 



specimen known; P. WyvilUi Theel, Sars'" Echinod.) 



from 34° 59' N., 33° 1' W., 4438 m. 



(" Challenger "). Besides these species one more was taken by 



the " Ingolf ", S.W. of Iceland, 2043 m., which will be described 



by Miss E, Deichmann under the name of Peniagone islandica. 



These 8 species are thus distinguished : 



Key to the N.E. Atlantic species of Peniagone.^ 



1. Deposits of body wall of two kinds : dorsally of the usual type, 

 with 4 inwardly bent arms and 4 slender outer projections, 

 all perfectly smooth ; ventrally, simple cross-shaped, robust 

 and very spinous rods. Dorsal veil large ('' Talisman " 

 Holothurioidea, p. 429, PI. XIII. 6, XIX. 24-35) 



P. vexillum Perr. 



Deposits of body wall all of the typical form (simple cross -shaped 



rods may be found among the typical in the deeper layer of 



the skin) ......... 2 



1 This key has been worked out by Miss E. Deichmann, to whom the 

 author is greatlv indebted for permitting its use here. 



2b 



