ONYCIIOTKITHIS. 109 



O. LiriiTENSTKiNTT, Fov. iuul Orl). PI. 18, figs. 21).5-'21)7. 



Head largo, with ciglit loiigitudiual postcro-dorsal I'idgos ; 

 body elongate, narrowed posteriorly, produced ; tins about one- 

 third the length of the body, triangular-sagittate, narrowly i)ro- 

 dueed behind ; sessile arms in length 4, 3, 2, 1, externally webbed ; 

 tentacles as in 0. Bergii (^ 0. Banki^ii). Shell with a long 

 end-conus. Length, ICi to IS inches. 



Mediterranean. 



The larger size, posteriorly produced fins, and different shell, 

 will distinguish this species from 0. Banksii. 



0. Krohnii, Yerany. PI. 73. figs. 298, 29i). 



Body stout, cylindrical, acuminate behind ; fins large, rhom- 



boidal, half the length of the body ; head with eight postero- 



dorsal ridges. Shell with a rather broad lamina. 



Length. iMi inch. 



Messi7ia. 



Notwithstanding ditferences of jn-oportion, etc., it may be 

 that this is the young of (). LichtenKteinii. Only a single speci- 

 men ol)taiued. 



0. DussuMiERT, Orb. PL 74, figs. 300, 301. 



Body elongate. sul»cylindrical, very finely' shagreened with 

 small, acute tubercles ; fins short, together rhomboidal ; sessile 

 arms unequal, lengths 2, 4, 3, 1 ; tentacles very slender, clubs 

 not expanded, with thirty hooks in two series. Shell narrow, 

 the apex with a very long, conical, acute, solid tip. 



Total length, 20 inches; of body, (i inches. 



200 miles N. of Mauritius. 

 O. RUTiLUS, Gould. PI. 74, fig. 302. 



Bod}'^ broad in front, narrowed to a point behind ; fins large, 

 heart rhomboidal, half as long as the body ; head large, sub- 

 quadrate ; sessile arms half as long as body, triquetrous, relative 

 lengths 4, 3, 2, 1 ; cupules on large pedicels nearly in a single 

 line ; tentacles one-third longer than the arms, stout, cylindrical, 

 with nine or ten hooks on long peduncles. Color very brilliant, 

 violet and salmon, with bluish and golden metallic refiections. 



Total length, 8'.5 inches. 



Near Sydney, N. S. Wales. 



Allied to 0. Banksii. but difterenf in proportions and in 

 coloring. 



