SYSTEMATIC HISTOEY OF THE INFUSOEIA. 



20 stout cost^ in 1-1200". KSA. p. 13. I 

 = FraqUana rofwidata, EB. 1844, p. 202 ; ' 

 EM. pi. 1. 1. £ 1. Fossil. Pliilippine | 

 Islands. 



O.jnnnatinn (E., K.). — Friistules three 

 to six times as long as broad; valves 

 linear, with rounded ends, and 15 stout 

 costc^ in 1-1200". KSA. p. 13. = Fm- 

 gilaria puinata, EA. p. 127; Microg. 

 many figm-es, Australia, Africa, and 

 America. Akin to O. striatum and O. 

 Syriacum, E. 



O. striolatum (E.,K.). — Frustules three 

 to six times as long as broad; valves 

 linear, constricted beneath the obtuse 

 capitate ends; striee about 18 in 1-1200". 

 KSA. p. 13. = Frayilaria striulata, EM. 

 t. 28. f. 58. Europe and Australia. Ehr- 

 enberg's figures in the ' Microgeologie ' 

 have the ends slightly attenuated, and 

 not capitate. 



0. Syriacum (E., K.). — Frustules eight 

 times as long as broad ; valves with 10 

 stri« in 1-1200". KSA. p. 13. = Fra- 

 yilaria Syriaca, EB. 1810, p. 16. Syria. 



O. ? ])ohjedrum (E. K.). — Frustules 

 oblong, angular (sexangular ?) ; three 

 times as long as broad ; strise very 

 fine. KSA. p. 14. = Frayilaria polyeclra, 

 EB. 1845, p. 77. Fossil. America. 

 1-900". 



O. amiMceros (E., K.). — Valves turgid 

 at the middle, with elongated, linear, 

 trmicate ends and pervious striae. KSA. 

 p. 13. = Frayilaria ampliiceros, EB. 



1844, p. 82; Microg. t. 18. f. 77. Vir- 

 ginia. 



O. yranulatum (E., K.). — With the 

 habit of O. amphiceros, but smaller; 

 valves with attenuated ends and granu- 

 lated fascias in striae. KSA. p. 13. = 

 Frayilaria yramdata, EB. 1844, p. 202. 

 Antarctic Sea. 



0.? G^Z«;zs(E.,K.). — Frustules striated, 

 short, gibbous at the middle, constricted 

 at the obtuse ends, and resembling the 

 figure of an acorn with its calvx ; striae 

 2 or 3 in 1-1200". KSA. p. U. = Fra- 

 qilaria Glans, E Inf. p. 185. Fossil. 

 Finland. 1-1150" to 1-570". 



O. anomahan (S.). — Filament tena- 

 cious ; valves linear, suddenly constricted 

 towards the roimded extremities ; costae 

 four to twelve. SBD. ii. p. 16, pi. 61. 

 f. 376. Alpine situations. Europe. Front 

 ^dew with punctate or denticulate mar- 

 gins. Internal cells, similar to those met 

 with in Meridion and Himantidium, are 

 frequent in this species. 



O. ancejjs (E.). — SmaU; valves linear- 

 oblong, constiicted beneath the subcapi- 

 tate apices. = Fraqilaria anceps, EA. 

 p. 127 ; F. Pteridium, EM. pi. 34. 5 b. 

 f. 10 ? North America. 



O. Cretce = Fraqilaria Cretce, EM. 

 pi. 53. 17. f. 9 ; F.paradoxa, EM. pi. 33. 

 15. f. 13 ? Australia, Europe, and Africa. 

 Valves linear-oblong, with rounded ends 

 and pervious transverse costae. 



Genus FEAGILARIA (Lyngb., K.).- — Frustules linear, united into a fila- 

 ment ; lateral valves smooth or faintly striated, linear-lanceolate or fusiform. 

 Fragilaria differs from Odontidium in the absence of costa) ; and the strice, 

 which are probably present in all the species, are so obscure that Klitzing 

 makes theii' absence one of the generic characters. Diadesmis may be distin- 

 guished from Fragilaria by the presence of a central nodule in the lateral 

 valves. Professor Smith justly regrets that in the subdivision of Fragilaria 

 sufiicient regard has not been paid to the signification of the generic name. 

 We consider that it would have been far better to have retained the name 

 for Fragilaria hyemalis, Lyngb. ( = Odontidium, K.), so remarkable for its 

 fragility. 



Feagilaeia capucina (Desni.). — Front 

 view naiTow linear, with obsolete or ob- 

 scure terminal puucta; valves lanceolate ; 

 striae obscure. KB. p. 45, 1. 16. f. 3. = 

 F. pectinalis, Ljaigb. t. 63; Ag Consp 

 Diat. p. 62 ; F. ^tenuis, Ag Consp Diat. 

 p. 63 ; F. Rhahdosoma, diojihthalma, mul- 

 tipuncfata, hipunctata, am/usta, scalaris, 

 and Jissa, E Inf. F. sepes, EM. t. 38. 1. 

 f. 8. Common, but generally in small 

 quantities and mixed wdtli other Diatoms. 

 Europe, Asia, Australia, Africa, and 



America, (ix. 173, 174.) A very vari- 

 able species. The fi-ustules are so much 

 compressed that it is difticidt to obtain 

 a good view of the valves ; but it may 

 usually be recognized in the fi-ont view 

 by its obsolete tenninal puncta. When 

 dried, it has a silvery lustre. Filaments 

 elongated. 



F. acuta (E.).— Valves linear, with 

 acutely cuneate apices ; striae wanting or 

 obscure ; front view linear. E Meteorp. 

 t. 2. f. 10; Microg. many figures. = -F. ea- 



