OF THE SUEIRELLEiE. 



801 



me. 

 the 



shade-like band, the inner series fainter. 

 GDC. p. 30, pi. 3. f. 51. Marine. Loch 

 Fine, Scotland. Professor Gregory sup- 

 poses that the appearance of a line which 

 divides the costa is caused by a ridge. 



C. fenestratus (Grev.). — Disc circular, 

 with ' marginal radiating costse divided 

 by a line into two series, the inner one 

 fainter and enclosing a central space 

 occupied by four lattice-like sculptures 

 formed by three or four bars crossing- 

 each other at right angles. Grev. in MJ. 

 V. p. 9, pi. 3. f. 4. Marine. West Indies. 

 The continuous costae are divided, as in 

 C centralis, by a line into two concentric 

 series, A species distinguished by the 

 *' four remarkable sculptures, exactly re- 

 sembling square windows in miniatiu'e, 

 the bars sharp and slender, and the panes 

 actuallv appearing as if they transmitted 

 light,"" Gr. 



C. Ecclesianus (Grev.). — Disc subcir- 

 cular, with a border of two concentric 

 series of very short, radiating costae, or 

 narrow-oblong cellules ; central space 

 with two rows of transverse broad bars, 

 separated by a median line, from each 

 end of which proceeds a semicircle of fine 

 strise. Gr. /. c. p. 10, pi. 3. f. 5. Mar: 

 West Indies. ^'Similar in size to 

 last, but somewhat more contorted, so 

 that when one portion of the valve is in 

 focus, the details of the remaining por- 

 tion are less visible. The valve is con- 

 cave ; the central portion, occupied b}^ the 

 two rows of bars, is nearly flat ; but on 

 each side of the rows, and at their termi- 

 nation, the disc is inflated, the lateral 

 inflations being unsculptured, the ter- 

 minal ones striated," Grev. 



C. hicostatiis (S.). — Disc suborbicular, 

 saddle-shaped, with from twenty to forty 

 unequal radiating costse, interrupted so 

 as to form two concentric series, enclos- 

 ing an oblong, smooth central space. 

 Ro. in MT. ii. pi. 6. f. 4 ; SBD. ii. p. 88. 

 Thames ; Norfolk. Diam. about 1-384". 

 Costfe distinct, their length, at sides, 

 about half the radius, at the ends much 

 shorter. Inner series less distinct. 



C, Cli/j^etis (E.). — Disc suborbicular; 

 rays_ numerous (40 to 100), radiating, 

 partially interrupted, and forming two 

 mcomplete concentric series ; the large 

 punctated central space divided by a 

 median smooth line. EM. pi. 10. 1. f. 1 ; 

 SBD. ii, p. 88. In fresh and brackish 

 \yaters ; also fossil, Asia, Africa, Ame- 

 rica, Europe, England. Original draw- 

 ings of this elegant species are given in 

 XVII. 516, 518, Diam, 1-576" to 1-216". 

 Costae pimctated, continuous at the ends. 



but interrupted at the sides, where they 

 form two series. In the central space 

 are two oblong sculptm-ed portions, sepa- 

 rated by the smooth median line. 



C, Remora (E,). — Disc suborbicular, 

 tortuous, with interrupted rays and a 

 smooth centre. KSA. p. 33.' Marine. 

 Baltic. D. 480". 



C. marginatm (E.). — Disc small, in 

 the middle smooth, subscabrous, fur- 

 nished in the margin with a double 

 series of cellules, the external fine, the 

 inner larger, evident, closed at the oppo- 

 site ends, open and radiated in the mid- 

 dle. KSA, p. 33, Maritime, King's 

 Island, India, Ceylon, 



C fastuosa (E,). — Disc suborbicular, 

 cm-ved ; costae subdistant, continuous, 

 divided into two concentric series, the 

 outer inflated, inner shorter, stalk-like, 

 enclosing a finely and transversely stri- 

 ated central space. KSA, p, 33. = C. 

 Thureti, BDC. pi. 1. f. 41 ; C. simulans, 

 Grev MJ. v. pi. 1, f, 41, Marine, Asia, 

 France, England. C. fastuosa is easily di- 

 stinguished from every preceding species, 

 except C. marginatus, by its finely striate 

 central space and the peculiar appearance 

 of its costae, which are divided by a line 

 into two parts, compared by Professor 

 Gregory to a lotus-flower on a stalk. Pro- 

 fessors Kiitzing and Gregory note its re- 

 semblance to Siirirella fastuosa ; we be- 

 lieve it, however, quite distinct, as, in 

 addition to its circular and bent form, the 

 central striae are finer and more numerous. 

 C. fastuosa varies considerably in size, 

 and in the comparative breadth of the 

 central portion, which is sometimes a 

 mere line, at others lanceolate, or even 

 oval. The costae are either interrupted 

 by the prolongation of the central por- 

 tion to the margin, or continued all 

 round. 



C. amhiguus (Gr.). — Disc suborbicu- 

 lar ; costae distant, reaching nearly to the 

 centre, partially interrupted at the mid- 

 dle ; in the centre an oblong depression, 

 within which is a short, linear-elliptical 

 blank line, Jamaica, Port Natal, Gr 

 MT. viii, p. 31, pi. 1. f, 5.= C. latus, Sh 

 MT. ii, pi. 1, f, 13, 



C, parvulus (S.). — Disc subcircular, 

 minute ; costae few (about twelve), in 

 length about two-thirds of radius; central 

 space obscurelv striated. SBD. i. p. 30, 

 pi. 6. f. 56. England, (xv. 22, 23.) We 

 have found this form generally accom- 

 panying C. fastuosa. Like that species, 

 it is sometimes oblong, and probably is 

 only a small variety. It is usually much 

 bent, and is the smallest species known. 

 3f 



