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IV. On the Structure and Characters of Loligopsis, and Account of a New Species (Lol, 
guttata, Grant) from the Indian Seas. By Roserr E. Grant, M.D., F.R.S. Ed., 
L.S., G.S., Z.8., &c., Professor of Comparative Anatomy and Zoology in the University 
of London. 
Communicated February 12, and July 23, 1833. 
No specimen of the Loligopsis of Lamarck appears to have been hitherto brought to 
Europe, and few naturalists are at present willing to admit the existence of this genus. 
Cuvier only mentions it in his ‘ Régne Animal’ (tom. iii. p. 14.) as a genus founded on 
drawings, which he considered of little authenticity, and makes no allusion to it in his 
Memoirs on the Anatomy of the Mollusca. M. Blainville (Malacologie, p. 367. note) 
rejects the genera Loligopsis of Lamarck and Leachia of M. Le Sueur, from their being 
founded on imperfect observations and figures, and from their affecting to present on 
the same animals the caudal fin of a Loligo along with only eight arms around the head, 
as in the Octopus. He regards such a combination of characters on the same individual 
as very doubtful. M. Férussac is of opinion that in the present uncertainty of naturalists 
regarding the Loligopsis, the species might be referred to the genus Cranchia, which is 
a Decapod with caudal fins. Lamarck, however, founded his genus Loligopsis on a 
drawing of a Cephalopod observed by Péron and Le Sueur in the South Sea, which had 
only eight equal arms around the head along with the caudal appendices of a Loligo ; 
that species he denominated Lol. Peronii (An. s. Vert., tom. vii. p. 659.). M. Le Sueur 
has founded a new genus Leachia on a drawing made by M. Petit from a similar Octopod 
with caudal appendices, obtained from the South Pacific (Journ. of the Acad. of Nat. 
Sci. of Philadelphia, vol. ii. Part I. p. 90.). As the Loligopsis of Lamarck, and the 
Leachia of M. Le Sueur, differ only in the length of the arms, M. Rang (Hist. des Mol- 
lusques, p. 87.) has very properly rejected this generic distinction, and regarded the 
two terms as synonyms; the Leachia cyclura of M. Le Sueur forms therefore a second 
species of Loligopsis in M. Rang’s use of the term, and the species I have now to describe 
forms a third of the same genus. 
All the Naked Cephalopods are Octopods, the disk which produces these feet by its 
division never producing a greater number than eight; but in many genera two re- 
tractile pedunculated tentacula are developed, and extend from within this outer sub- 
divided disk, and generally between the first and second anterior arms on each side, 
which has given rise to the division termed Decapoda in this class. The tentacula, 
however, never assume the form of the other feet. The peculiarity of the Loligopsis 
is therefore not the want of any of the usual eight feet, but the want or imperfect de- 
