900 



SYSTEMATIC HISTOET OF THE IXFUSOHIA. 



N. tumens (S.). — Inflated, elliptic, with 

 the ends suddenly contracted into short, 

 obtuse beaks ; striae indistinct, 36 in 

 •001". SD. i. p. 52, pi. 17. f. 150. Brack- 

 ish water. England. 



N. pusilla (S.). — Small, inflated, ellip- 

 tic, suddenly contracted into short, conic 

 beaks ; stii?e distinct, punctate, radiant, 

 26 in -001". SD. i. p. 52, pi. 17. f. 52. 

 =iN. gastroides, Greg. MJ. iii. p. 40, pi. 4. 

 f. 17. Brackish water ? Britain. Prof. 

 Gregory distino-uished his N. gastroides 

 from this species by its stouter habit, 

 larger size, and having a brown colour 

 even in balsam; but we unite them as 

 Professor Smith has done, being imwill- 

 ing to add another doubtful species to 

 this group, which we believe is already 

 too numerous. 



N, Anglica (Ralfs). — Minute, elliptic, 

 suddenly constricted beneath the round- 

 ish capitate ends; striae very distinct, 

 punctate, radiate, reaching the median 

 Ime, 24 in -001". = N. tumida, SD. i. 

 p. 53, pi. 17. f. 146. 



N. Carassius (E.). — Small, inflated, 

 broadly lanceolate, with the ends sud- 

 denly contracted into short, conical 

 beaks ; striae wanting or indistinct. EA. 

 p. 130, pi. 2. 2. f. 11. France, America. 

 Is smaller than N. amjMshfena. 



N. capitaia (E.). — Minute, ^^dth in- 

 flated centre, and short, obtuse, beak- 

 like ends; striae diverging, 10 in 1-1200". 

 E Inf. p. 179, pi. 13. f. 20. = Pinmdaria 

 capitaia, EM. pi. 35 a. 1. f. 4. Europe, 

 Asia, Australia, America. 1-1150" to 

 1-576". 



N. Seinen (E.). — SmaU, elliptic-ob- 

 long, slightly contracted into the broad, 

 obtuse ends ; striae obsolete or apparent. 

 EA. pi. 4. 2. f. 8 ; in EM. manv hgures ; 

 SD. i. p. 50, pi. 16. f. 141. i3,'^stri£e di- 

 stinct, = Pinmdaria Semen, EM. Europe, 

 Asia, Africa, America, 



N. cequalis (E., K.). — Inflated, eUiptic- 

 lanceolate, suddenly contracted at the 

 ends into nipple-like points ; striae fine. 

 KSA. p. 77. = Pinnularia (eqiialis, EA. 

 131 ; EM. many %ures. Europe. Lough 

 Mourne deposit, Iceland. 



N. diomj)Iiala (E.). — Striated, short, 

 broadly lanceolate, suddenly conti^acted 

 into obtuse beaks ; median nodule trans- 

 verse, divided bv a longitudinal line into 

 two parts. EA. p. 132, pi. 3. 7. f. 25. 

 America. 



N. Gastrum (E., K.). — Small, striated, 

 inflated, elliptic, contracted at the ends 

 into short conical beaks ; striae radiant. 

 KB. p. 94, pi. 28. f. 56. = Pinmdaria 

 Gastrum, EM. several figures; Pi7i- 



nularia Placentida, EM. several figures. 

 Asia, Africa, America. 



N. hirostrata (Greg.). — Ventricose, 

 elliptic-oblong, with shortly rostrate 

 apices ; striae tine, close, radiant, reaching 

 nearly to the median line. M J. iii. p. 40, 

 pi. 4. f. 5. Scotland. 



N. tceniata (E.). — Small, inflated, 

 elliptic, suddenly contracted into minute, 

 rounded, conical beaks ; pinnides strong, 

 forming a narrow marginal border. = 

 Pinmdaria tceniata, EM. pi. 39. f. 95. 

 The pinnules separated from the median 

 line by a broad blank space. Perhaps a 

 Mastogloia. (xv. 15.) 



N. hiceps (E.). — Small, turgid, lance- 

 olate, slightly constricted into obtuse, 

 conical apices ; striae wanting- or indi- 

 stinct. EA. p. 130 ; EM. many tigm-es. 

 Em*ope, Africa, America. Rather more 

 slender than N. amplxishcena. 



N. crassula (Niigeli). — Smooth, ellip- 

 tic, Tvdth capitate apices ; front view 

 broadlv linear, trmicate. 1-720". KSA. 

 p. 890."^ S\\dtzerland. 



N. scidpta, EM.pl. 10. 1. £5. Bohe- 

 mia, Asia, America. Ventricose, sud- 

 denly tapering into short, broad, obtuse 

 beaks, the median line interrupted by 

 the indefinite nodule, which extends on 

 one side in a semicrucial smooth band ; 

 the rest of the surface granidated. Front 

 view linear, mtli rounded angles and 

 gibbous sides. 



N. signata (E.). — Minute, inflated, 

 prolonged into naiTOw beaks ; striae 

 radiant, reaching the median line, the 

 six central ones stronger. = Pinmdaria 

 signata, EM. pi. 34. 6 a. f. 7. Florida. 



N. RosteJlum (S.). — Small, ventricose, 

 oval, with the apices produced into point- 

 like beaks ; striae indistinct, 80 in -001". 

 SBD. ii. p. 93 = A^ apimlata, Greg. MJ. 

 iv. pi. 1. f. 13. Britain. 



2 t Valves lanceolate. 



N. Crassinervia (B.). — Minute, lance- 

 olate, Tvith shortly rostrate apices ; striae 

 wanting or indistinct. SD. i. p. 47, pi. 31. 

 f. 271. France, Britain. 



N. rhjncJiocephala (K.). — Slender, 

 lanceolate, with longly rostrate apices ; 

 striae wanting or obscure. KB. p. 152, 

 pi. 30. f. 35 ; SBD. p. 47, pi. 16. f. 132. 

 Europe. Is longer and more slender than 

 N. cryptocephala, with more produced 

 apices, (vii. 68.) 



N. le2itorhgnclms(E.).—^mQi\, smooth, 

 linear-lanceolate, with straight, subacute, 

 longly rostrate apices. EA. p. 130. 

 Mexico. Akin to N. dirhynchus, but 

 with lonorer beaks. 



