788 



SYSTEMATIC HISTORY OF THE INFUSOEIA. 



slightly attenuated towards the rounded 

 apices, nodule obsolete; striae 26 in 

 •001". SBI). ii. p. 98. Marine. Scot- 

 land. 



S. acuta (E.). — Front view exactly 

 linear, truncate ; valves linear, stiiated, 

 suddenly acuminated near the apices. 

 EA. 1. 1. 2. f. 22. America, Asia, Au- 

 stralia, and Africa. 1-144". 



S. Oxijrhynclms (K.). — Front view 

 linear ; valves linear, narrower, suddenly 

 contracted into a beak at the ends. KB. 

 p. 66, t. 14. f. 9-11. Gei-many. Di- 

 stinguished fi'om S. acuta by its con- 

 stricted ends. 



S. vitrea (K.). — Front view vdih di- 

 lated apices ; valves linear, wath sud- 

 denly attenuated, obtuse ends. KB. 

 p. 66, t. 14. f. 17. France. Distin- 

 guished from aS'. Oxyrhynchus only by its 

 dilated ends in the fi'ont view, Kab. 



S. amphirhynclms (E.). — Large ; front 

 view linear, not dilated at the ends; 

 valves contracted into obtuse beaks. 

 EA. t. 3. 1. f. 25. Fresh water. Eu- 

 rope, Africa, and America. 1-120" to 

 1-96". No large, median, smooth space. 



S. prcemorsa (E.). — Frontviewbroadly 

 linear, with truncated, cmieate apices ; 

 valves linear, with roimded cuneate ends. 

 EA. t. 3. 6. f. 11. Mexico. 



S. defonms (S.). — Valves linear or 

 linear-elliptical, suddenly consti'icted 

 towards the produced and often distorted 

 extremities; nodule obsolete; striae 36 

 in -001". SBD. ii. p. 98. Fresh water. 

 Sussex. 



S. JJlna (E.). — Front view exactly 

 linear ; valves linear, slightly attenuated 

 near the obtuse apices. E Inf. t. 17. f. 1 ; 

 SBD. i. p. 71, pi. 11. f. 90. Fresh water. 

 Europe, Asia, Australia, Africa, and 

 America, (x. 184.) 1-280" to 1-100". 

 Striai 24 in -001", Sm. 



S. splendens (K.). — Large, elongated; 

 front \'iew with dilated truncate ends ; 

 valves lanceolate, obtuse. KB. p. QQ, 

 t. 14. f. 16. = 6'. radians, SBD. i. p. 71, 

 in part. Fresh water. Europe, Asia, 

 and Africa. 1-72". Differs from S. 

 Ulna merely in its dilated apices, Rab. 



S. Banica (K.). — Slender ; front view 

 with dilated, truncate ends ; valves lan- 

 ceolate with slightly clavate apices. 

 KB. p. 66, t. 14. f. 13. Stagnant waters. 

 Europe. 1-140". Is only a more slen- 

 der form of >S', sple?ide)is, Rab. 



S. mesocampa (Breb.). — Size and form 

 of S. TJlna, but in the lateral view Hexed 

 at the middle. KSA. p. 44. France. 



S. capitata (E.). — Valves linear, with 

 the extremities dilated into a triangular 



head; striae 23 in -001". E Inf. t. 21. 

 f. 28 ; SBD. i. p. 72, pi. 12. f. 93. Fresh 

 water. Em-ope, Asia, Africa, and Ame- 

 rica. (lY. 29; X. 185.) Very large; length 

 1-120" to 1-40". 



S. longicejjs (E.). — Very large, in form 

 approaching very near to'^iS'. cajntata, but 

 wath styliform, produced apices. ERBA. 

 1845. Fresh water. America. 1-12" 

 to 1-144". 



6 * Frusttdes attachedhy a distinct, mostly 

 persistent, stipes ; pseudo-nodule obsolete 

 or indefinite. 



t Frustules in fan-shaped clusters on a 

 short, mostly simple, stipes. 



S. Acus (Kiitz.). — Slender, smooth; 

 front view slightl}' attenuated, truncate ; 

 valves very narrow lanceolate, acicular. 

 KB. p. 68, 1. 15. f. 7. Hamburgh. 1-960". 



S.fatniliaris (K.). — Smooth, distinctly 

 tabeilate and flabellately disrupted ; 

 front view slightly attenuated near the 

 trimcate ends ; valves lanceolate, acute. 

 KB. p. 68, t. 15. f. 12. France. 1-320". 



S. parva (K.). — Minute, smooth, nar- 

 row linear, truncate ; valves narrow lan- 

 ceolate. KB. p. 67, t. 15. f. 9. Marine. 

 Italy. 1-960". 



S. socialis (Rab.). — Front view linear, 

 with truncated, cuneate ends; valves 

 lanceolate, distinctly striated. Rab D. 

 p. 56, t. 4. f. 22. Fresh water. Italy. 



S. Gallionii (E.). — Frustules large, on 

 a thick, convex stipes ; valves lanceo- 

 late; striae 36 in -001", interrupted by a 

 median line. E Inf. t. 17. f. 2 ; SBD. 

 i. p. 74, pi. 30. f. 265. Marine. Em-ope, 

 Asia, Africa, and America, (xn. 34, 36.) 

 1-120" to 1-100". 



S. fasciculata (Ag., K.). — Frustules ta- 

 bulate, on a thick, hemispherical stipes ; 

 front view linear, wdth subattenuate, 

 truncate apices ; valves lanceolate. KB. 

 p. 68, t. 15. f. 6.=Diato7na fasciculatmn, 

 Ag CD. p. 51 . Marine. Common. 



S.tabulata (Ag., K.). — Frustules large, 

 on a thick, abbreviated stipes; front 

 view broadly linear, ti-uncate ; valves 

 lanceolate, with subcapitate apices ; striae 

 marginal, 27 in -001". KB. p. 68, t. 15. 

 f. 10 ; SBD. pi. 12. f. 96. = Diatoma 

 tahulatmn, Ag CD. p. 50. Marine. 

 Europe. 



S. affinis (K.). — Frustules subtabulate, 

 on a hemispherical stipes; front view 

 slender, linear, with subattenuate trun- 

 cate apices; valves lanceolate, acute, 

 with 32 marginal striae in -001". KB. 

 p. 68, t. 15. f. 6, 11 ; SBD. i. p. 73. 

 Marine. Em-ope. 1-320". FrustiUes 



