86 P. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



2(3. D. siibfinctii A. S. (1.S74). — V. slightly constricted in the middle. with nioie or less 

 distinctly cuiieate ends. L. O.oh to 0,ii'j2; B. 0,0235 to 0,025; at the coiistr. 0,02 to n,.i2-j mm. 

 Central iiodule large, quatlrate; its horns parallel or convergent at tlie ends. Furrows moderately 

 broad, narrovved at the ends. with faint traces of costfE. Costtc (i to 7 in 0. 01 mm., crossed by a 

 longitudiual line. — Nav. suhcincta A. S. N. S. D. Pl. II f. 7. Atl. XIII f. 41; LXIX f. 32. 

 Grun. D. Franz Josephs Land p. 56 (4) Pl. I f. 38, 39. Nav. didyma Lägst. Boh. D. f. I a. 



Mariue: Franz Josephs Land (Grnn.), Kära! Finmark! North Sea! Balearic Islands! 

 Adriatic! Madagascar ! Monterey, Cal.! Fossil: Aegina (Atl.), Japan (Brun a. Temp.), ^Maryland 

 (Ueby Coll.)! St. Monica (Deby CoU.)! 



27. D. (liscrepiius A. S. (1875). — V elliptioal. L. 0,03; B. O,oii mm. Central nodule 

 broad, quadrate, its horns divergent at their basis, convergent at the ends. Furrows broad. Costa- 

 Il in 0,01 mm., crossed by a longitndinal costa(?). — Nav. discr. A. S. Atl. VIII f. 8. 



Marine: Campeachy Bank (Atl.). 



Unknown to the author. The description is from the hg. in atlas and I am not sure if 

 the longitndinal line aci'oss the eosthf really be a costa. 



'2>^. D. binaria A. S. (1875). — V. slightly constricted, with broad, rounded ends. L. 0,042; 

 B. 0,022; at the constr. 0,02 mm. Central nodnle large, quadrate, its horns parallel, approximate. 

 Fm-rows very broad, not dilated in the middle, with double longitudinal rows of puncta. Costa? 

 6 in 0,01 mm. crossed by a longitudinal costa. — Nav. hinaria A. S. Atl. XII f. 62. 



Marine: Java (Atl.). 



29. D. (lenita A. S. (1881). — V. sligthly constricted. L. 0,ii6; B. 0,o3-; at the constr. 

 0,0 3 mm. Central nodule large, quadrate; its horns parallel. Furrows broad, linear. Costte 6 in 

 0,01 mm. crossed by a broad longitudinal costa(?). — Nav. demta A. S. Atl. LXIX f. 31. 



Marine, fossil: St. Monica, Cal. (Atl.). 



Unknown to the author. The fig. in Atl. does not distinctly show if the longitudinal band 

 is, as here accejjted, a costa or a row of ocelli. In the latter case this form may probably be 

 placed near D. Pandura. 



30. D. exemta A. S. (1875). — V. panduriform, with tongue-shaped segments. L. O.oss 

 to 0,136; B. 0,032 to 0,042; at the constr. 0,026 to 0,o3 mm. Central nodule quadrate, rather 

 large; its horns parallel. Furrows linear. Costte 5 in 0, 01 mm., crossed bj' a longitudinal line. 

 on the furrows faint or reduced to puncta. — Nav. exemta, A. S. Atl. XI f. 2<s, 29. 



Marine: Tamatave (Brun Coll.)! Tahiti! Kerguelens Land (llae Coll.)! Campeachy Bay! 

 Fossil: Oamaru, New Zealand! S:ta Monica (Deby Coll.)! 



Var.? crahroniforniis Grun. (1875). — L. 0,o83; B. 0,025; at the constr. 0,oi6. Costa^ ti in 

 0,01 mm. — Nav. crabronif. Atl. XI f. 24. 



Marine: Gulf of Mexico (Atl.). 



Var. diyrediens Cl. — L. 0,048 to 0,o65; B. 0,022; at the constr. O.oi to 0,oi4 mm. Horns 

 somewhat divergent. Costa; 8 in 0, 01 mm. 



Marine: China (Thum.)! Hungary, fossil (Deby CoU.)! 



31. D. coarctata A. S. (1875). — V. deeply constricted in the midtUe. L. O, o: to 0,i ; B. O.026 

 to 0,035; at the constr. 0,oi36 to 0,oi8 mm. Central nodule quadrate, with parallel horns. Fnrrows 

 narrow, linear, with a row of large puncta. CosttE 3 — 4 in 0, 01 mm., crossed by a longitudinal 

 line. — Nav. coarcf. A. S. Atl. XI f. 30, 31, 32, LXIX f. 11. 



Marine: Campeachy Bay (Atl.), Cape Horn (Petit), Hungary, fossil (Pant.). 



This is a very suspicious form. The figure recently published by A. Schmidt in Atl. 

 (CLXXIV f. 22) has very much the appearance of being a strongly corroded specimen of i). Crabro 

 var., or of JD. Dirhombus, if that form be anything but a small D. Crabro. 



