86 p. T. CLEVE, SYNOPSIS OF THE NAVIOULOID DIATOMS. 



26. D. siibcincta A. S. (1874). — V. slightly constricted in the middle, with more or less 

 distinctly oiineate ends. L. O.oe to 0,o92; B. 0,o235 to 0,025; at the constr. 0,u2 to 0,022 mm. 

 Central nodule large, quadrate; its horns parallel or convergent at the ends. Furrows moderately 

 broad, narrowed at the ends, with faint traces of costfB. Costse 6 to 7 in 0,oi mm., crossed by a 

 longitudinal line. — Nav. suhdncta A. S. N. S. D. PL II f. 7. Atl. XIII f. 41; LXIX f. 32. 

 GrRUN. D. Franz Josephs Land p. 56 (4) PL I f. 38, 39. Nav. didyma Lagst. Boh. D. f. 4 a. 



Marine: Franz Josephs Land (Grun.), Kara! Finmark! North Sea! Balearic Islands! 

 Adriatic! Madagascar! Monterey, CaL! Fossil: Aegina (AtL), Japan (Brun a. Temp.), Maryland 

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



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

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

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



Marine: Campeachy Bank (AtL). 



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

 the longitudinal line across the costse really be a costa. 



28. D. biiiaria A. S. (1875). — V. slightly constricted, with broad, rounded ends. L. 0,042; 

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

 Furrows very broad, not dilated in the middle, with double longitudinal rows of puncta. Costae 

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



Marine: Java (AtL). 



29. D. demta A. S. (1881). — V. sligthly constricted. L. O.iie; B. 0,037; at the constr. 

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

 0,01 mm. crossed by a broad longitudinal costa(?). — Nav. demta A. S. Atl. LXIX f. 34. 



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 accepted, 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. 0,o85 

 to 0,136; B. 0,032 to 0,042; at the constr. 0,026 to 0,03 mm. Central nodule quadrate, rather 

 large; its horns parallel. Furrows linear. Costte 5 in 0,oi mm., crossed by a longitudinal line, 

 on the furrows faint or reduced to puncta. — Nav. exemta A. S. Atl. XI f. 28, 29. 



Marine: Tamatave (Brun Coll.)! Tahiti! Kerguelens Land (E,ae Coll.)! Campeachy Bay! 

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



Var.? craironiformis GtRun. (1875). — L. 0,083; B. 0,025; at the constr. 0,oi6. Costse 6 in 

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



Marine: Gulf of Mexico (AtL). 



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

 somewhat divergent. Costse 8 in 0,oi mm. 



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



31. D. coarctata A. S. (1875). — V. deeply constricted in the middle. L. 0,o7 to 0,i ; B. 0,o26 

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

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

 line. — Nav. coarct. 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 D. Crdbro 

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



