ES 
a 
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221 
This communication having extended far beyond the length that I 
at first contemplated, notwithstanding that I have limited myself in 
most cases to the distinctive peculiarities of the skull, it will readily 
be seen that, had I entered upon the whole osteology of the order, or 
even introduced in every instance the characters by which the genus 
or species may be known externally, I should have swelled this little 
monograph to such a degree as almost to preclude its insertion in the 
“ Proceedings’ of the Society, and entailed upon myself an amount of 
labour from which I would by no means shrink, but fear I shall be 
compelled to defer until more favourable opportunities present them- 
selves; but I trust that the little I have as yet accomplished may 
afford the naturalist a clearer insight into the relations of the living 
Edentata among themselves, and with those that formerly peopled 
the portion of the world which was then, as now, the principal abode 
of this remarkable group. 
Pimlico, July 1851. 
4. A Monocrapu or ScuTus, A GENUS OF GASTEROPODOUS 
MOLLUSCA, BELONGING TO THE FAMILY FissuRELLID2. 
By Artuur Apams, R.N., F.L.S. erc. 
Genus Scurus, De Montfort. 
Animal with the head proboscidiform ; tentacles thick and subu- 
late, with the eyes on tubercles at their outer bases; mantle reflexed 
over the sides of, and nearly covering, the shell; sides of foot with a 
series of short cirrhi. 
Shell oblong, scutiform, flattened ; apex dorsal, oblique, posteriorly 
inclined ; margin of aperture sinuated in front ; muscular impression 
horse-shoe shaped, open anteriorly. 
Parmophorus, Blainv.— Dascinus, Rafin.—Seutellites, Auct.— 
Scutum, Sow. jun.—Parmophora, Desh.— Emarginula, sp. Sow. — 
Patella, sp. Lamk. 
1. Scurus uneurs, Linn. 
Patella unguis, Lim. Mus. Ludovic. Ulric. Regin. p. 69. no. 419. 
—Patella ambigua, Chemn.— Seutus antipodis, Montf.— Parmo- 
phorus australis, Lamk.—Parm. elongatus, Blainy. 
Hab. New Zealand. Mus. Cuming. 
2. Scurus ELonGatus, Lamarck. 
Patella elongata, Lamk. Ann. du Mus. i. p- 310.—Parmophorus 
elongatus, Lamk. Hist.—Emarginula elongata, Sow. Gen. 
Hab. East Australia. Mus. Cuming. Also occurs fossil. 
3. Scurus GRANULATUS, Blainy. 
Parmophorus granulatus, Blainy. Bullet. des Scienc. 1817; Lamk. 
Hist. An. s. Vert. vol. vii. pt. ii. p.5; Reeve, Conch. Syst. pl. 139. f. 4. 
Hab. Port Essington, on the rocks, low water. Mus. Cuming. 
