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XXXI. Observations on the “ Bitentaculate Slug” of New Zealand (Limax bitentacu- 
latus, Quoy and Gaimard; Janella antipodarum, Gray; * Aneiteum Slug” ?, Mac- 
donald). By Cuarrzs Knient, Esq., F.L.S. 
Read June 2nd, 1859. 
Auckland, New Zealand, 
27th December, 1858. 
DEAR Str, 
I Have lately compared Mr. J. D. Macdonald’s observations on the Bitentaculate Slug 
found at Aneiteum (Annals and Mag. Nat. Hist. 2 ser. xviii. p. 38, 1856) and Dr. Gray's 
description of Janella antipodarum (Annals and Mag. Nat. Hist. 2 ser. xii. p. 414, 1853) 
with the living Gasteropod found in New Zealand, and trust that the following notes 
and the accompanying drawing will interest the members of the Society. 
The New Zealand mollusk is little more than an inch in length. The mantle (?) covers 
the whole of the upper surface. The space which Dr. Gray describes as existing between 
the edge of the mantle and the foot, is on the under surface of the animal; so that the 
edge of the mantle forms the outline of the body as seen from above. The mantle (?) is 
mottled with light-coloured spots, the larger of which are at regular intervals, and are at 
times elevated above the surface in sharp conical points (fig. 14). The “ raised margin ” 
of Dr. Gray’s description is due to the effects of aleohol. 
In alcohol the animal becomes subcylindrical, and answers to the description of 
Dr. Gray and to that of Lamarck (Anim. sans Vert, 2nd ed. vol. vii. p. 723, Limax biten- 
taculatus, Quoy). 
The aperture of respiration (4, fig. 3) is on the right side of the slightly depressed roof 
of the pulmonary sac. There are four small, semitransparent, calcareous (?) granules in 
the anterior wall of the pulmonary sac (fig. 13); and immediately anterior to the sac is a 
small foramen (a, fig. 3), affording passage to a fluid which flows in pulsatory waves over 
its roof. Generally this pulsatory movement occurs at regular and frequent intervals ; 
and the wave extends around the pulmonary aperture, as if a limpid fluid were pro- 
pelled under the glutinous secretion which covers and protects the body of the mollusk. 
The buccal mass is armed above with a single horny plate or tooth (figs. 7 , 8). In feed- 
ing, the animal forces forward the buccal mass, and scrapes or hoes up with the horny 
plate the surface of the substance it is feeding on. 
The lingual sae, instead of being furnished with the single, symmetrical, ume 
appendage of the common Slug of these Islands, has posteriorly two c P 7 ; 
convolute appendages armed with transverse rows of dental processes (figs.11,12). The 
sac itself is furnished with a complete armature of rasps (figs. 9, 10) placed in conma 
transverse parallel rows, which meet in the median line at a very obtuse angle. eg jte 
has several minute teeth, and is set diagonally in the row, as are also the spine-like plat 
from which the minute rasps project (fig. 10). 
