0¥ THE SUEIKELLE^. 



797 



marginal costae in 1-1200" ; alae incon- 

 spicuous. KB. pi. 7. f. 1-4 ; SBD. pi. 9. 

 f. 70. Europe, America. Front view 

 broadly cuneate, truncate. 1-1200" to 

 1-560." 



S. minuta (Breb.). — Minute, ovate- 

 elliptic, with inconspicuous alae and 14 

 marginal costae in -001". SBD. i. p. 34, 

 pi. 9. f. 73. France, England. -0005" to 

 •0009". Kiitzing unites this fomi with 

 S. ovata; but M. de Brebisson informs 

 us that he is able to distinguish the two 

 species when m situ at the first glance ; 

 that the stratum of this species is black 

 and very mobile, whilst that of S. ovata 

 is brown, and adheres more firmly to 

 the soil. 



S. salina (S.). — Minute, ovate-oblong, 

 with numerous minute marginal costae 

 and obsolete alse. SBD. i. p. 34, pi. 9. 

 f. 71. Marine or brackish waters. Eng- 

 land. Front view wedge-shaped. 



S. suhsalsa (S.). — Minute, ovate-lan- 

 ceolate, with 8 distinct costae and 30 

 strias in 1-1200" ; alae conspicuous. SBD. 

 i. p. 34, pi. 31. f. 259. =6'. pijgmmi, EM. 

 pi. 35 A 8. f. 4 ? Fresh or brackish 

 waters. England. 



S. pmnata (S.). — Minute, narrow, 

 ovate-oblong or somewhat clavate, with 

 large, subdistant marginal costae ; alae 

 obsolete. SBD. i. p. 34, pi. 9. f. 72. 

 Aquatic. Lewes. Front view narrow 

 cimeate. 



4 * Lateral view with broadly rounded, 

 rarely unequal, ends. 



S. Lamella (E.). — Large, narrow 

 elliptic, with nearly equal, broadly 

 rouiided ends ; intramarginal striae and 

 granulose median area ; front view nar- 

 row linear, truncated. EM. pi. 15 a. 

 f. 49. Lough Moume deposit. 1-210" 

 to 1-180". Ehrenberg's figure has no 

 median line. 



S.iiosowia(E.). — Narrow elliptic, with 

 broadly rounded ends, a narrow margin 

 of fine striae, and a smooth median area 

 with a median longitudinal line. EM. 

 pi. 33. 14. f. 25. Maritime. India. Three 

 times as long as broad. 



S. Patella (K.).— Elliptic-oblong, with 

 equal, rounded ends, and four or five mar- 

 ginal stria3 in 1-1200". KB. t. 7. f. 5. 

 Fossil at Franzensbad. 



S. Peruviana (E.). — Large, elliptic- 

 oblong, with equal, rounded ends, and 

 about 12 verv short, obsolete, marginal 

 costae in 1-1200". KB. t. 29. f. 72. Peru. 



S. amphiamhlya, EM. pi. 14. f. 34. 

 Berlin, The figure shows a large elliptic 

 form with equal, rounded ends, intra- 



marginal crenations, and strong, paraUel, 

 transverse costae, which do not quite 

 reach the median line. 



S. Mississipica, EM. pi. 35 a. 8. f. 5. 

 America. Ehrenberg's figure is large, 

 eillptic-oblong, with equal, roimded ends, 

 and paraUel transverse costae, separated 

 by a naiTOw linear, longitudinal median 

 band. 



5 * Lateral view with rounded ends ; costce 



ivith dilated outer portion, and median 



space Jinely striated. 



S. fastuosa (E.). — Elliptic, with 

 rounded ends, rather distant costae, in- 

 flated towards the margin, and a trans- 

 versely striated, lanceolate median space. 

 Greg M J. iii. p. 30, pi. 4. f. 41. Marine. 

 Common. Eui-ope, Asia, Africa, Ame- 

 rica. Distinguished from all the pre- 

 ceding species by its inflated costae re- 

 sembling stalked flowers, and by the 

 striated median space, which is very 

 variable in breadth. Diflers much in 

 size, and is sometimes nearly orbicular -, 

 we have never seen it ovate, as described 

 by Professor Smith. 



S. lata (S.). — Large, broadly linear- 

 elliptic or somewhat panduriform, with 

 broadly rounded ends, a transversely 

 striated median area, and distant cost89 

 externally dilated. SBD. i. p. 31, pi. 9. 

 f. 61. = Campylodiscus productus, John- 

 ston. Marine. Not uncommon. England. 

 Differs from *S'. fastuosa in its form, and 

 usually in its larger size ; but the mark- 

 ings are similar in both. As Professor 

 Gregory finds intermediate states, they 

 may be, as he supposes, mere varieties. 



S. eximia (Grev.). — Linear-oblong 

 with rounded ends, about 18 delicate 

 costae on each side, reaching the narrow 

 linear-lanceolate, transversely striated 

 median space. Grev M J. v. p. 10, pi. 3. 

 f. 6. Marine. West Indies. This ex- 

 tremely delicate and hyaline Diatom, 

 Dr. Greville informs us, approaches S. 

 lata in form, slight constriction, and a 

 striated central space, but differs in every 

 other respect. The costae equidistant, 

 and as fine as those of S. Gemma j alae 

 naiTow, but conspicuous. 



Doubtful or undescribed ^ecies. 



S. ? Cocconeis, EM. pi. 35 a. 8. f. 3. 

 Marine. India, Africa. This species, 

 according to the figure, is small, elliptic, 

 with obtuse ends, and parallel transverse 

 costae separated by a smooth, narrow- 

 lanceolate median space. 



S. Jenneri (Hassall). — Front view 

 linear, with rounded ends, and distant, 



