a point ; aperture consisting of a small produced siphon; colour, when divested of its 

 brown epidermis, pure white and glossy. Length one-tenth of an inch. Inhabits 

 the sea at Sandwich. 



2. A r . deccmlocularia. 

 Shell with ten distinct, nearly globular articulations ; slightly arcuated, and ending 



in a long tapering articulation, in which the septa are hardly distinguishable ; covered 

 with a reddish-brown epidermis. Length a tenth and a half of an inch. We have 

 received this from the south coast of Devon ; but too late for insertion in the plate. 

 This is doubtless the same shell which Montagu considers a variety of N. subar- 

 cuata, which he had from Sandwich. 



3. N. radicula, pi. I, f. 28.— Orthocera radicula.— Tirst Ed., pi. 52, f. 28 ; Nau- 

 tilus radicula ; Montagu, p. 197, pi. 6, f. 4. 



Shell subconic, elongated, with six subglobose deeply divided artieulations; the 

 upper one much larger than the others, and egg-shaped, smooth, opaque-brown, 

 and the aperture provided with a small siphon, with the apex extended to a conic 

 point. From Sandwich. 



Montagu mentions varieties of this species, having from two to five articulations. 

 We have not seen these, and therefore cannot speak concerning them. The follow- 

 ing distinct species is only considered a variety by that able naturalist. 



4. N. oetolocularia, pi. 1, f. 25. — Orthocera radicula. — First Ed., pi. 52, f. 25 ; 

 Nautilus radicula ; variety. Montagu, 198, pi. 14, f. 6. 



Shell with eight round sub-compressed articulations, the superior one nearly 

 spherical, with a small circular aperture in the apex ; the remaining articulations 

 gradually lessening, and the last one somewhat pyriform and pointed at its extremity. 

 Colour cream-white. Found at Sandwich and the south coast of Devon. 



In our first edition we followed Montagu, in considering this only a variety of 

 .V. radicula. 



5. N. spinulosa, pi. I, f. 26 Orthocera spinulosa.— Tint Ed., pi. 52, f. 26; 



Nautilus spinulosusi Montagu, Sup. p. 86, pi. 19, f. 5. 



Shell with three globose, deeply divided articulations, covered with spines, which 

 incline to the posterior end ; the superior bulb somewhat elongated, in the form of a 

 siphon ; colour pale chestnut. 



Montagu mentions a variety of this shell, of which he possessed a drawing by Mr 

 Henry Boys, which was subarcuated and taper, with eight articulations ; which were 

 rather tuberculated than spined. We would be inclined to consider this a distinct 

 species, under the trivial name of tuberculata. 



Genus 4 — Orthocera. — Lamarck. 



Shell elongated, straight, or a little arcuated, subconical ; gene- 

 rally ribbed, with longitudinal, external grooves ; chambers formed 

 by transverse septa, perforated by a tube, which is either central or 



marginal. 



Subdivision I. — Ribbed. 



I. 0. costata, pi. I, f. 17 First Ed., pi. 52, f. 17; Nautilus costatus ; Mon- 

 tagu, p. 199, pi. 14, f. 5. 



Shell straight, subcylindrical, tapering slightly towards the posterior termination ; 

 with twelve convex articulations, each provided with four equidistant, strong longi- 

 tudinal ribs, running continuously the whole length of the shell ; aperture extended, 

 in the form of a short conic siphon. Length a quarter of an inch. Found on the 

 coast of Kent. 



Montagu mentions a variety, with only six articulations, for the same locality. 



2. O. septemcostata, pi. I, f. 24. — 0. costata, variety, First Ed., pi. 52, f. 24 ; 

 Nautilus costatus ; BTontagu, Sup. variety, p. 83, pi. 19, f. 2. 



Shell nearly cylindrical, with five oblong-ovate articulations, each provided with 

 seven libs, running continuously the whole length of the shell ; posterior end trun- 

 cated, with the points of the ribs projecting beyond its margin ; anterior end termi- 

 nated by a slender cylindrical process as long as the first articulation, destitute of any 

 opening, the aperture being situated at the truncated extremity. 



Montagu mentions a variety with five articulations, and four ribs only. 



3. O. jugosa, pi. I, f. 13.— First Ed., pi. 52, f. 13 ; Montagu, p. 198, pi. 14, 

 f. 4. 



Shell subarcuated, subcylindrical, tapering ; with nine, ridged, subglobose, some- 

 what elongated articulation- ; aperture extended to a small conic siphon, the extreme 

 joint at the inferior end rather longer than the contiguous ones ; colour opaque- 

 brown. Length a little more than an eighth of an inch. The ridges do not extend 

 quite to the top of the articulations. 



4. 0. hicarinata.- — Nautilus bicurinatus.- -Montagu, Sup. p. 86. 

 Shell arcuated, lubcylindrical, with eleven subglobose, bicarinated articulations, 



or furnished with a slight longitudinal rib along the arc, and another on the opposite 

 side; the larger end terminated by a produced siphon; the articulations gradually 

 decrease towards the posterior end, which is rounded ; length an eighth of an inch ; 

 diameter at the largest part about tne same. Found at Sandwich. 



5. O. linearis, pi. I, f. 14-15.— First Ed., pi. 52, f. 14-15; Nautilus linearis; 

 Montagu, Sup. p. 87, pi. 30, f. 9. 



Shell straight, a little compressed, linear, slightly tapering ; provided with numer- 

 ous longitudinal ribs, which take an oblique direction, and scarcely extend half the 



MOLLUSCA. [Cephalopoda. 



length of the shell. It is of a glossy, smooth, and pellucid white, except along the 

 sides, and at the divisions of the cells, where it is opaque ; ther • aro about fourteen 

 •lightly oblique, and not quite regular septa; anterior extremity smooth, and ter- 

 minated by a product d siphon ; posterior end rounded. Length nearly a quarter of 

 an inch, breadth about an eighth of its length. Found on the shell-bank at Dunbar. 

 Frith of Forth. ' 



Subdivision If. — Destitute of llibs. 



6. O. recta, pi. I, f. 16, in, 20. — First Ed., pi. 52, f. 16, 19, 20; Montagu, 

 p. 197, and Sup. p. 82, pi. 19, f 4 and 7. 



Shell straight or very slightly arcuated, with perfectly smooth, slightly divided 

 articu'ations ; tapering a little to the posterior termination ; aperture situated in a 

 small produced siphon at the anterior extremity. Found at Sandwich ; very rare. 



Family IV Sphehulacea. 



Shell globular, spheroidal, or oval ; with the volutions mutually 

 enveloping, or the cells contiguous, and forming a tunic. 



Genus 5 Biloculina. — D' Orbigny. 



Shell ovate-globose, with two transverse cells, involving the axis. 



1. B. oblonga, pi. LVI, f. 38-39.— Luge.na oblonga First Ed., pi. I, f. 38,39 ; 



Vermiculum oblongata; Montagu, p. 522, pi. 14, f. 9. 



Shell oblong, oval, somewhat compresse.1 ; with a longitudinal suture on one side, 

 which divides the sh -11 into two parts; on the opposite side the middle compartment 

 is surrounded by a faint depression, which separates it from the exterior one, and is 

 more elevated, aperture oval, slightly produced, wiih a yellow margin; general co- 

 lour opaque, glossy white. Length not half a line. Found in sand from Saicomb 

 Bay, Devonshire ; rare. 



2. B. elliptica, pi. LVI, f. 23.— Miliola elliptica First Ed., pi. 1, f. 23. 



Shell elliptical, a little compressed, clear, smooth and glossy ; the internal cham- 

 bers shining through, giving it the appearance of being externally grooved ; size not 

 a line. Found at Dunhar by General Bingham. 



3. B. lactea, pi. LVt, f. 23. — Mdiula luctca.— First Ed. ; Vermiculum lacteum ; 

 Montagu, p. 522 ; Scrpula tenuis ; Walker, f. 5. 



Shell thin, smooth, glossy, egg-shaped, slightly compressed ; pellucid, with milk- 

 white veins. Length half a line C>iast of Devonshire. 



4. B. marginata, pi. LVI, f. 25 — Renoidea marginata. — First Ed., pi. 1, f. 25. 

 Vermiculum marginatum ; Montagu, p. 524 ; Walker, pi. 1, f, 7. 



Shell globular, a little compressed, surrounded by an elevated zone; colour 

 white, transparent and glossy. Size not half a line. Found at Reculver, and on 

 the coast of Devon ; very rare. 



Genus 6 Triloculina — 2)' Orbigny. 



Shell generally ovate-globose, with three transverse cells involv- 

 ing the axis. 



1. T. glubra, pi. LVI, f. 20-21.— Renoidea glabra.— First Ed., pi. 1, f. 20-21. 

 Shell nearly circular, three lobed, the two external ones longest, and involving 



the third; smooth, transparent and glossy. Size about a line. Found at Dunbar 

 by General Bingham; rare. 



2. T. rotundata, pi. LVI, f. 14-15 Renoidea rotundata First Ed., pi. 1, f. 



14-15. 



Shell perfectly globular, smooth, shining and transparent ; milky white, with 

 three lobes, the external ones largest. Size not a line. Found at Dunbar by 

 General Bingham ; very rare. 



3. T. bicornis, pi. LVI, f. 24 Miliola bicornis First Ed., pi. 1, f. 24. 



Serpula bicornis; Montagu, p. 519. 



Shell three chambered, the middle one small, the outer one3 rounded, considera- 

 bly larger, and investing it on one side, and longitudinally striated on the longer 

 side from the aperture, which is contracted ; mouth small, orb.cular ; colour opaque ; 

 white. Length one line. Found at Sandwich and Reculver. 



4. T. perforata, pi. LVI, f. 26.— Mdiula perforata — F.rst Ed., pi. 1, f. 26 

 — Vermiculum perforatum; Montagu, p. 519 Scrpula bicornis; Walker, f. 3. 



Shell three chambered ; central compartment flat, thin, and perforated, with a se- 

 milunar disc on one side, and a larger curved chamber on the ether ; colour white, 

 opaque, and glossy. Found at Sandwich and Cornwall ; very rare. 



5. T. striata, pi. LVI. f. 27 Miliola striata — First Ed., pi I. f. 27. 



shell with three compartments, the two outer ones investi g the others; the 



whole are longitudinally striated ; yellowish white; not a line in length. Found at 

 Belton sands, near Dunbar, by General Bingham. 



6. T. intnwra.pl. LVI. f. 18-19 Miliola minute First Ed/, pi. 1, f. 18-1:'. 



Shell three chambered, the middle one flat on one side, and raised on the other ; 



it is entirely invested by the outer valves, one of which is sleuth r, and the other 

 broad, and tapering, with three or four strongly marked longitudinal stria; ; size 

 about half a line. Found at Dunbar by General Bingham. 



