KONGL. SV. VET. AKADEMIENS IIANDLINGAK. HAND 26. N:() 2. 59 



Var. Fenzlii Grun. (1863). — Lanceolate, soniftimas with .snhrostrate (mhIk. Fj. 0,07 to 1 -j ; 



B. 0,028 to 0,042 mm. Area narrow, dilated around the nodule. Stri;e, 11 to 14 in 0,o 1 mm. 

 Longitudinal lines median. Nav. elcgans (tRUN. Verb. !>!(!(» p. ')34 PI. iV f. 87. Nav. Fcndii 

 Grun. Verh. 18(53 ]>. 153. Nav. (imphish. v. FmsUi Grun. in V. H. Syn. p. 102 PI. XI F. 5. 

 N. Grunoirii O'Meara B. D. p. 362 PI. XXXI f. 17. 



Brackish water: Neusiedler See, Himgary (Grun.), Rostock, fossil! Ceylon (Weissflog Coll.)! 

 Calcutta (Ueby Coll)! Batavia! Jamaica! St Martin, W. Lid.! Guatemala, fossil! St. Monica, fossil 

 (Dr. Rae Coll.)! 



All these forms are closely connected, so that it seems to me impossible to regard them 

 as distinct species. They are also nearly akin to the two following species, C. hirittata and C. 

 permaffna, of which the latter is, by intermediate forms, connected with (J. formosa. 



34. C. bivittata Pant. (1889). - V. lanceolate. L. 0,o8 to 0,1.5; B. 0,031 to 0,(14 mm. 

 Axial and central area uniting in a broad, lanceolate space. Strife 10 (middle) to 12 or 13 (ends) 

 in 0,0 1 mm., slightly radiate. Longitudinal lines double. — N. {prcgouica var.?) hivittata Pant. II 

 p. 43 PI. V. f. 83. 



Brackish and marine: Hungary, fossil! Atlantic City, N. Jers. foss. (Deby Coll.)! 



35. C. perinagiia Bail (1850). — V. rhombic-lanceolate, sometimes with slightly triimdn- 

 lated margins. L. 0,1,5 to 0,22; B. O,o.55 to 0,03.5 mm. Axial and central areas uniting in a 

 more or less broad, irregularly lanceolate space. Striae 9 to 10 in 0,oi mm. slightly radiate. 

 Longitudinal lines broad or double, median. — Pinnul. perm Bail. Smiths. Cont. 1850 p. 40 PI. II 

 f. 28, 38. Nar. permagna Ralfs Pritch. Inf. p. 907. Lewis Proc. Ac. n. sc. Philad. 1861 p. 70 

 PI. II f. 11. Greville "t. M. S. XIV p. 127 PI. XII f. 18 to 21, 1866. V. H. Syn. p. 102 PI. XI f. 1. 



Brackish water: Anvers (V. H.). N. America (New- York to Florida and Gulf of Mexico)! 

 This large and beautiful species passes over by intermediate forms to N. formosa, and 

 seems also to be nearly akin to C. hirittata. 



36. €. Blisenii Cl. N. Sp. — V. rhombic-lanceolate, with subacute ends. L. 0, 1 as ; B. 0,o38 

 mm. Axial area narrow. Central area moderately large, orbicular, without any markings. Stritu 

 13 in 0,01 mm., radiate, in the ends slightly convergent. Longitudinal lines approximate to the 

 areas. — PI. IV f. 4. 



Brackish water (mouths of I'ivers): Cameroon, Africa! 



This species is named in honour of Mr Dusen, a Swedish traveller in AVestei'n Africa, who 

 procured me an interesting gathering from that country. This beautiful form greatly resembles 



C. permagna, but differs by the closener of its longitudinal lines to the areas. 



37. C. madagascarensis Cl. (1S90). — V. broadly lanceolate. L. 0,(»o.5; B. (),ub mm. 

 Median line with distant central pores. Axial and central areas uniting in a narrow, lanceolate 

 space. Median line bordered by thick silicious ribs. Striai 9 in 0,oi mm. radiate troughout, in- 

 distinctly punctate. Longitudinal lines three, of which the median is the strongest (and differs 

 from the others). — N. madag. Cl. Diatomiste I p. 23 PI. IV f. 2. 



Marine: Madagascar! Columbo, Ceylon (Letourneur Coll.)! Java! 



This is a remarkable species, having some resemblance to C. amphislxena var. Fcnslii, from 

 which it is however (juite distinct. Of the three longitudinal lines the median has tlie appearence 

 of a narrow furrow, separating the flatter axial part of the valve from the sloping exterior 

 part. The other lines are formed by small knots on the striae. 



38. C. biclavata C'l. a. Grove (1891). — V. convex, gibbous in the middle and with clavate 

 ends. L. 0,12 to 0, le; B. 0,0 18 mm. Axial area broad, dilated around the central nodule to an 

 irregularly rounded space. Strict 10 in 0,oi mm., divergent in the ends, else almost parallel. 

 Longitudinal lines distinct, median. — Cl. a. Grove Diatomiste I p. Q'o PI. X f. 7. 



Marine: Macassar Straits (Grove Coll.)! 



