KONGL. SV. VRT. AKADKMIKNS IIANDTJN(!A1{. BAND 27. N:() 3. 175 



line, reaching to the margin, no areas and line striu;, radiate thronghont, about 2r)in(),oi mm. 

 Diat. of Finland p. 51 PI. Ill f. 8 (J)?) 



Fresh water: Sweden (Ryssby in Calmar Liin, haltic freshwater deposit fT'om the Ancyhi.s- 

 epoch), Abo, Finland! 



5. C. diriipta Gkeg. (1857). — Broadly elliptical to almost orbicular. Upper V. with 

 linear, usually sigmoid, axial area. Lower V. with more or less distinctly sigmoid median line 

 and the terminal fissures in contrary direetions. Centr.al nodule transversely dilated to an out- 

 wardly narrowing fascia. 



Var. typica Cl. — L. (),i);ir, to O.oni; B. 0,018 to 0,05 mm. Upper V. with linear nf)t sig- 

 moid axial area. Stria? about 17 in (),oi mm. punctate; puncta forming undulate longitudinal 

 rows. Lower V. with very slightly sigmoid median line. Central area transversely dilated to a 

 fascia not reaching to the margin. Stride 20 in 0,oi mm. — C. diriipta GtREg. D. of Clyde p. 491 

 PI. IX f. 25. A. S. N. S. D. PI. Ill f. 2L V. H. Syn. p. 133 PL XXIX f. 13 to L5. C. diaplunia 

 ^V. Sm. B. J). p. 22 PL XXX f. 254 partim (1853)? C. ddicafa A. S. Atl. CXCVl, 24? Probably 

 also (J. ncca)ii('a, (J. limbata and C. fasciata Ehb. 



Marine: Greenland! North Sea! Mediterranean Sea! China! Behring's Island! Tahiti ((Irun.), 

 Cape of Good Hope (Grun.), California! Galapagos Islands! (Jolon! 



Var. duhia Grun. (1867). — Smaller. Stria? 22 0,01 mm. Central nodule rarely, terminal 

 nodules never, transversely dilated. — Novara p. 14. 



Marine: S:t Paul (Grun.). 



Var.? Bdtnteyeri Jan. (1894). — L. 0,04; B. 0,o2 7 mm. Upper V. with lanceolate, not sig- 

 moid area. Strise 12 in 0,oi mm. crossed by 4 to 8 blank ])ands. — A. S. Atl. CXCVI, 22, 23. 



Marine: Leton Bank (Atl.), Pensacola (Atl.)? 



Var. flcxella Jan. Rab. (1862). — L. 0,02 to 0,0:3; B. 0,02 to 0,o3 mm. Upper V. with 

 narrow, lanceolate axial area. Striie 20 in 0,oi mm. crossed on each side of the area by about 4 

 linear, curved blank bands. Lower V. with sigmoid median line, reaching to the ends, and trans- 

 verse central area. Striai about 19 in 0,oi mm. — ('. flc.vcUa Jan. Rab. D. Honduras p. 7 PL I 

 f. 11. C. dir. var. flex. V. H. Syn. PI. XXIX f. 16, 17. 



Marine: ]\rediterranean Sea! Adriatic! Honduras (Jan. Rab.). 



Var. atUarciica Grun. (1881). — L. 0,042; B. 0,o3u mm. Upper V. with narrow, linear axial 

 area. Strife about 15 in 0,oi mm., punctate; puncta forming longitudinal rows, about 13 in 0,oi 

 mm. Lower \. with nearly straight median line, ending at some distance from the margin in trans- 

 verse terminal areas, turned in contrary directions. Stria?. 11 in 0,oi mm. distinctly punctate; 

 puncta forming irregularly undulating longitudinal rows, about 11 in 0,oi mm. — V. H. Syn. 

 PL XXIX f. 18, 19. C. dir. var. major Grun. Novara p. 14? 



Marine: New Zealand (Grun.), China! 



Var. californica Cl. — L. 0,o4o to 0,o7; B. 0,o.3 to 0,oo mm. Upper V. with slightly sig- 

 moid, lanceolate axial area not dilated in the middle. Strife 11 to 16 inO.oi mm. of large, distant 

 ])uncta, forming undulating, longitudinal rows, about 9 in 0,oi mm. — A. S. Atl. CXCVI, 17, 18(?) 



Marine: California fossil at S:ta Martha and S:ta Monica (L)eby Coll.)! Moron, Spain, fossil 

 (Grove Coll.)! 



Var. decipiens Cl. (1873). — L. 0,o25 to 0,06; B. 0,034 to 0,04 mm. Upper valve with sig- 

 moid axial area in the middle dilated to an orbicular space. Strise 16 to 20 in 0,oi mm. punctate; 

 puncta (10 in 0,oi mm.) forming irregularly decussating rows (14 in 0,oi mm.). Lower V. with 

 sigmoid median line reaching nearly to the ends. Strise 11 to 12 in 0,oi mm. punctate; puncta, 

 about 14 in 0,01 mm., becoming larger oiitwards. — C. dccip. Cl. D. Arct. Sea p. 14 PI. I f. 6 

 (Lower V.). C. ardicum Cl. 1. c. PL II f. 11 a (Upper V.). 



Marine: Arctic America! Greenland! Finmark! Behring's Island! 



