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 vidll 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 Monograph of Scutus, a genus of Gasteropodous 



MOLLUSCA, BELONGING TO THE FAMILY FlSSURELLID^. 



By Arthur Adams, R.N., F.L.S. etc. 



Genus Scutus, 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. — Scutellites, Auct. — 

 Scutum, Sow. jun. — Parmophora, Desh. — Emarginula, sp. Sow. — 

 Patella, sp. Lamk. 



1 . Scutus unguis, Linn. 



Patella unguis, Linn. Mus. Ludovic. Ulric. Regin. p. 69. no. 419. 

 — Patella ambigua, Chemn. — Scutus antipodis, Montf. — Parmo- 

 phorus australis, Lamk. — Parm. elongatus, Blainv. 



Hab. New Zealand. Mus. Cuming. 



2. Scutus elongatus, Lamarck. 



Patella elongata, Lamk. Ann. du Mus. i. p. 310. — Parmophorus 

 elongatus, Lamk. Hist. — Emarginula elongata. Sow. Gen. 

 Hab. East Australia. Mus. Cumuig. Also occurs fossil. 



3. Scutus granulatus, Blainv. 



Parmophorus granulatus, Blainv. Bullet, des Scienc. 1817; Lamk. 

 Hist. An. s.Vert. vol. vii. pt. ii. p. 5; Reeve, Conch. Syst. pi. 139. f. 4. 

 Hab. Port Essington, on the rocks, low water. Mus. Cuming. 



