312 nKConi>s of tiik ai'stramax mtsktm. 



Oiichidiuvi tonijanniii, Quoy and Gainiard, Voy. Astrolabe, Zool., ii., 1832, 



p. 210, pi. XV., tigs. 17-18. Id., .Semper, Keis. im. Ai-ch. Phil., iii., 



LaudinolL, v., 1880, p. 258, taf. xix., figs. 2, 9, taf. xxii., figs. 1, 2, 10. 



/</., Desliayes, Hist. uat. Aiiim. sans Vert., vi. (2), 1836, p. 709. Id., 



Cuuniugliaru, Encycl. Britainiica, 11th ed., 1910, xi., p. 252, fig. 62. 



///., Bergh, Challenger Rep., Zuol., x., pt. 1, 1884, p. 142, pi. vi., fig. 



19, pi. viii., figs. 1-2. 

 Oui'ldium [leruni (Cuvier), Plate, Zoul. Jalirb., Anat., vii., 1893, p. 172. 

 Veronia iiianritiana, Blaiuville, Man. de Make, 1825, p. 489, pi. xlvi., fig. 



7, 1827. hi. Diet. Sci. Nat., xxxviii., 1825, p. 523, pi. Ixiii., fig. 7, 



1816-30. 

 / Peronia rorpidenla, CJoiild, Moll. Wilkes U.S. Expl. Exp., xii., 1852, p. 293. 

 Feronia toixjensix (Quoy and Gaimard), Gray, Fig. Moll. Anini., iv., 1850, 



p. 117. 

 Feronia lomjana (Quoy and Gaimard), Tapparone Canefri, Faun. Mai. N. 



Guinea, 1883, p. 214. Id., H. and A. Adams, Gen. Rec. Moll., ii., 



1858, p. 235, pi. Ixxxi., tig. 3. 



Exteniul character^:. — Body elongate oval, not strongly arched. 

 Mantle border smooth in smaller specimens, and somewhat notched in 

 larger ones. Head large, and projecting freely as much as six to eight nun. 

 beyond the mantle border. Tentacles short and conical, and capable ol' 

 reti-action into a more broadly conical base ; eyes at the tips surrounded 

 by a darker ring. Hyponota equal to the greatest width of the foot sole. 



Average size: Largest specimen examined, length 104 mm., breadth 

 l^ii mm., height 20 mm., greatest width of the foot sole 29 mm. ; smallest 

 specimen examined, length 50 mm., breadth 35 mm., height 20 mm., 

 greatest width of the foot sole 10 mm. 



Mantle t^<: nipt are. — The mantle is liberally covered with laige and 

 small papillae, and with coarse and fine granules irregularly arranged. In 

 some areas the papilla? are more or less grouped ; the papilla' when 

 gi'ouped and in the middle tiehl, stiiiul sis much as '.] mm. I'l-oni the back, 

 while the isolated and other pii pi I lu' average 1 mm. in liciglit. Thegi'oups 

 of papiihe ai'e ol" definite rormatioii, and {iomprise (1) gi-oups having a 

 central pajtihi around which are arranged lour to six |)apilla' ol" the same 

 si/.e ; (2) groups where the central papilla is actually made up of four 

 small papilla?, around which are five to seven bunches of tliii'c jjapilhv in 

 each bunch ; (3) gioups of three to four papillfe appealing as snnill tufts. 

 The majority of the i)apilla' beardoi'sal eyes, either singly oi- in irregularly 

 arranged groups; they ai'c more numei-ous in the middle and ]>osterior 

 field, but are present even around the mantle margin. In large specimens 

 bi-anchial plumes are well developed, close to the posterior mantle border. 



Colour. — The ground colour above is olive, with an irregular patteiii 

 of lighter and darker patches. The papilhv and granules conform to (lie 

 change of colour, and in numy cases they may be half the ground colour 

 and half the pattern colour. The foot and the underside are regularly 

 yellowish ; the upper side of the head being i-ather nu)re olive in colour. 



Fiisitioii nj oiteniiiija. — The nnile genital opening is situated in a trans- 

 verse slit varying to P5 mm. in length. The anus is situated on an anal 

 papilla emanating from the loot groove; the tail of (he foot is ilecply 



