0\i'lllli|ll>,+' m.'KTNAIl,. 315 



iviid brown. In juvenile specimens, broad yt^'low and brown bands and 

 spots are predominant ; while in adult specimens tiie ground colour pre- 

 vails. The foot is dirty yellow in coloui-, while the head is bluish-black. 

 The hyponota are olive, and the respiratory opening is linged with yellow. 



I'diitiuii of i>iie)ii)ufs. — Typical of the genus. 



Anatomy. — Described by Plate. 



Group rliavitcter. — Anterior portion of the penis with Ciutilaginous 

 hooks; a cartilaginous tube is present. 



Lofdliti/. — Vaigiou and Rawak, New (Jniiica (tj)uoy and riainiard) ; 

 Pouape, Sonth-westei-n Pacific (l*late). 



Oncihimum STKKNSi'Kui'ii, Semper. 



( hirliidium Kteeiistrapii, Semper, Reis. im Arch. Phil., iii., Ijaiidinoil., vi., 



1882, p. 265, taf. xx., fig. 5, taf. xxi., fig. 22, 24. 



Oiii'idlflla steenstrupii (Semper), Tapparone Canefri, Faun. Mal. N.Guinea, 



1883, p. 213. 



Eternal diaracters. — Body shape globular, back not strongly arched. 

 Mantle boi'ders smooth. Head large; tentacles short and conical. Hypo- 

 nota smaller than the greatest widtli of the foot sole. 



Average size : Length 1"9 cm., breadth 16 cm., height 1 cm. ; greatest 

 width of the foot sole 15 cm. 



Mantle ^^ndptnre. — The mantle appeals to be smooth, but is finely 

 granulated. Small groups of papilla? to the right and left of the middle 

 field bear from five to seven eyes. 



Colonr. — The ground colour of the mantle is light brown, witli an 

 irregular pattern of darker flecks. The underside is yellowish-brown, 

 the hyponota and upper side of the head being darker in colour. 



Position of openinija. — The anus is situated on a small papilla and is 

 well protected by the tail of the foot ; the respiratory opening in the 

 median line is half way between the anal papilla and the mantle border. 

 Male and female genital openings typical of the genus. 



Anatomy. — Described by Semper. 



firowp character. — Cartilaginous hooks and tube present in the penis. 



Lorality. — Ponape, South-western Pacific (Semper, (lodeifi-oy 

 Museum) ; New Guinea (Semper, Tapparone Canefri). 



Onchididm melanopneumox, Berijli. 



OnrliiiJium melanopneiimon, Bergh, Challenger Rep., Zool., x., pt. 1, 1884, 

 p. 129, pi. iv., figs. 25, 27, pi. v., figs. 1-27, pi. vi., lig. 5-18, 20, 21. 

 }(/., Joyeux-Laffuie, Arch. Zool. Exper. (2), iii., 1885, p. i\. 



? Oncidlam peroni, Plate, Zool. Jahrb., Anat., vii., 1893, p. 172. 



External characters. — Body rounded, back not strongly arched. Mantle 

 boi'ders smooth. Head large, tentacles long. Hyponota smooth and 

 smaller than the greatest width of the foot sole. 



Average size: Length 6*5 cm., breadth 4 cin., Height 2 5 cm.: 

 greatest width of the foot sole 3 cm. 



