780 



SYSTEMATIC HISTOHY OF THE INFUSORIA. 



agreed vnth their definitions. It is, however, probable that his characters 

 may rather belong to a family than to a single genus, his sections forming 

 genera. The sigmoid forms were placed by Ehi-enberg in ]N"avicula, and by 

 Kiitzing, in his earlier work (Kiescl. Bacil.), in Synedra. Subsequently, how- 

 ever, in his ' Species Algarum,' Klitzmg removed them from Synedra, and, under 

 his old name of Sigmatella, placed them with the Pragilarieae because they are 

 not affixed and have pervious transverse striae. 



* Minute : front view strait ; valves ar- 

 cuate tvith a row of dots on the ventral 

 mar (/in. 



NiTzscHiA ampldoxys (E.). — Valve 

 linear lanceolate, arcuate, with convex 

 dorsum, concave venter, and attenuated, 

 subrostrate, acute apices; strite 30 in 

 •001", terminating in dots at the ventral 

 margin. SBD. i. p. 40, pi. 13. f. 105. 

 = Eunotia amphioxys, EA. p. 125. Fresh 

 water, very common. Ehreuberg gives 

 upwards of 200 habitats in Europe, Asia, 

 Australia, Africa, and America. 



N. vivax (S.). — Valve linear lan- 

 ceolate, arcuate, with rostrate apices ; 

 striae distiuct, 30 in -001", terminat- 

 ing in marginal dots. SBD. i. p. 41, 

 pi. 31. f. 267. Fresh or brackish water. 

 England. 



N. parvula (S.). — Valve with central 

 constriction, obscure puncta, and pro- 

 duced apices ; striee faiut, 70 in -001". 

 SBD. i. p. 41, pi. 13. £ 106. Marine. 

 Sussex. 



N. minutissima (S.). — Valve linear, 

 with distinct puncta and prominent 

 acute apices ; striae obscure, 72 in -001". 

 SBD. i. p. 41, pi. 13. f. 107. Fresh 

 water. Beachy Head. 



^.Biance (E.). — Valve linear, arcuate, 

 with convex dorsum, concave venter, and 

 produced slightly reflexed apices ; striae 

 13 in 1-1200", terminating in dots on 

 the ventral margin. = JEunotia Biance, 

 ERBA. 1840, p. 14; Microg. pi. 35 a. 

 2. f. 9. Fresh water. Europe, Asia, 

 Africa, and America. 



N. amjyJiikpta (E.). — Valve linear, 

 arcuate, with convex, smooth dorsum, 

 slightly concave, striated ventral margin, 

 and acute, gradually attenuated, slightly 

 reflexed apices. = JEunotia ainjjJitlcpta, 

 ERBA. 1845, p. 363; Microg. pi. 34. 8. 

 f. 4. Japan and China. 



N. virgata (Roper). — Valve linear 

 lanceolate, slightly arcuate, with pro- 

 duced, slightly recurved, obtuse apices ; 

 stiiae distinct," 26 in -OOl', dilated at in- 

 tervals into ridges on the ventral margin. 

 Roper JMS. vi. p. 23, pi. 3. f. 6. Ma- 

 rine. Tenby. Diflers from N. ampJii- 

 oxys and N. vivax by the strife being 



dilated into bands instead of terminating 

 in puncta, Roper. 



2 * Frustules constricted at the middle, 



N. constricta (K.). — Front view ob- 

 long, slightly constricted at the middle 

 and tapering towards the somewhat 

 truncate ends ; keel very eccentric ; striae 

 obscm'e, 60 in -001". = Synedra con- 

 stricta, KB. p. 64, t. 3. f. 70 ; Nitzschia 

 duhia, SBD. i. p. 41, f. 112. Marine. 

 Europe. 



N. Bntoinon (E.). — Elongate, thick, 

 striate, oblong with constricted middle 

 and obtusely cuneate ends. = Synedra 

 Untomon, EM. pi. 34. 2. f. 5. Em-ope, 

 Asia, Australia, Africa, and America. 



N. 2j/«;irt (S.). — Front view linear 

 lanceolate, with attenuated middle and 

 acutely cuneate ends ; valves acutely 

 linear lanceolate, mth a single row of 

 puncta and 56 obscure striee in -001. 

 SBD. i. p. 42, pi. 15. I 114. Brackish 

 water. Europe. 



N. Brlyhtwellii (Kitton). — Valves 

 broad linear- oblong, with obtuse, shortly 

 attenuated ends, slightly constricted 

 middle and interruptedly striate margin ; 

 surface imder a low power granular, 

 under a higher, punctato-striate ; strife 

 transverse, 25 to 30 in -001". Brackish 

 water. Sien'a Leone. Kitton in lit. 

 (viii. 7.) 



N. latestriata (Breb.). — Front view 

 large, broad linear-oblong, with a central 

 constriction and broadly rounded ends ; 

 valves narrow lanceolate, with a central 

 keel, double row of puncta and 56 di- 

 stinct strife in -001" . = Aniphiprora late- 

 striata, Breb. in KSA. p. 93 ; Nitzschia 

 hilohata, SBD. i. p. 42, pi. 15. i. 113. 

 Marine. Europe. 



N. panduriformis (Greg.). — Broad 

 linear-oblong, ^\dth constricted middle, 

 acuminate ends, and punctuated mar- 

 gins ; striae fine, about 48 in -001", trans- 

 verse and oblique, GDC. p. 57, pi. 6. 

 f 102. Marine. Scotland. There is a 

 faint indication of a double keel in the 

 middle of the valve. The striation is 

 similar to that of Tryblionella constricta ; 

 but the present form is larger, and di- 

 stinguished by marginal puncta : still it 



