102 p. T. CLEVB, SYNOPSIS OF THE NAVICULOID DIATOMS. 



To this group of forms belongs probably B. ornata {Nav. ornata A. S. Atl. LXIX f. 5. 

 K ornata spirifera A. S. Atl. CLXXXIV f. 25) from S:ta Monica and Monterey in California. It 

 is a large and beautiful form, of whieb only corroded specimens seem to be known. At least I 

 have hitherto not seen any uninjured specimen. 



C. Forms with broad lunulce. 



Var. multicostata Grun. (1860). — V. strongly constricted, with elliptical to rhomboid seg- 

 ments. L. 0,09 to 0,2 1 ; B. 0,03 to 0,06; at the constriction 0,oi8 mm. Lunulee very broad. 

 Costffi 4 to 5 in 0,oi mm. — Nav. multicostata GrRUN. Verb. 1860 p. 524 PL III f. 13. A. S. Atl. 

 XI f. 14, 15, 16, 18, 19, 20, CLXXIV f. 6, 7. Nav. Crahro A. S. Atl. LXIX f. 1, 2. V. H. 

 Syn. p. 83 PI. IX f. 2. A. S. N. S. D. PL I f. 5, 6 II f. 4 (corroded). Nav. crahro var. oranensis 

 Atl. LXIX f. 3 (corroded). Nav. polita Brun D. esp. n. p. 37 PI XV f. 1 (corroded). 



Marine: North Sea (Norway)! Mediterranean Sea! Red Sea! Madagascar! Ceylon! Labuan! 

 Java! Samoa! Sandwich Islands (Atl.)! Gralapagos Islands! Cape Horn (Petit)! West Indies! Fossil 

 Eungary! Moravian Tegel! Oran (Atl.), iEgina (Atl.), Nankoori! S:ta Monica Cal. 



Var. nankoorensis GrRUN. (1881). — V less constricted, with cuneate ends. L. 0,12; B. 0,0 53; 

 at the constriction 0,o42 mm. Costee 4,5 in 0,oi mm. — Nav. Crahro var. nanhoor. A. S. Atl. 

 LXIX f. 4 (corroded). 



Marine: Nankoori, fossil (Atl.). 



Var. O'Meari Grun. Ms. — V. elliptical, not constricted. L. 0,13.5; B. 0,058 mm. Lunulse 

 very broad. Costse parallel, 4 in 0,oi mm. — PL II f. 12. 



Marine: Macassar Straits (Grove Coll.)! Seychelles (Grun.), South Sea (Van Heurck Coll.)! 



Grunow sent me several years ago a sketch of an elliptical Diploneis from Seychelles under 

 the name of Nav. O'Mearii, which agrees in essential points with the form from Macassar Straits, 

 having, as it has, very broad lunulse, filling almost the whole valve. L. 0,o9; B. 0,o3 mm. 

 Costee 6 in 0,oi mm. 



Var.? Gihelii A. S. (1874). — V. slightly constricted, with tongue-shaped segments. L. 0,09; 

 B. 0,033; at the constriction 0,o26 mm. Lunulae broad, forming a biconstricted space. Costse 4 in 

 0,01 mm. — Nav. Gihelii A. S. Probet. f. 13 PL XII f. 73. 



Marine: Campeachy Bay (Atl.). 



Var. minuta Cl. — L. 0,05 6; B. 0,024; at the constr. 0,oi6 mm. Costse 6 in 0,oi mm. — 

 A. S. Atl. XII f. 71. 



Marine: Samoa (Atl.). 



Var. perpusilla Cl. — L. 0,04; B. 0,oi8; at the constriction 0,oi2 mm. Costse 8 in 0, 01 mm. 

 — A. S. Atl. XII f. 72. 



Marine: North Sea (Atl.). 



Var.? confecta A. S. (1875). — V. small. L. 0,04; B. 0,009; at the constriction 0,0075 mm. 

 Lunulse very large. Costse 9 in 0,oi mm. — Nav. confecta A. S. Atl. XII f. 46. 



Marine: Campeachy Bay (Atl.). 



Var.? Dirhomhus A. S. (1875). — V. strongly constricted, with subrhdmboid segments. 

 L. 0,076 to 0,13; B. 0,024 to 0,038; at the constriction 0,oi2 to 0,oi5 mm. Lunulse large, lunate. 

 Costse 4 to 6 in 0,oi mm Ocelli not distinct. — Nav. Dirh. A. S. Atl. XI f. 21, 22; LXIX f. 9 

 (10 corroded). 



Marine: Gulf of Mexico (Atl.), Pelew Island (Atl.). 



The connection of this form with the others is not certain, as the figures in Atl. do not 

 shew the marginal row of ocelli. It seems as if this form were to var. multicostata what var. 

 suspecta is to var. separabilis. Bipl. coarctata may be a corroded Dirhomhtis, which however 

 am unable to decide, not having had an opportunity of comparing specimens. 



79. D. biseriata Cl. N. Sp. — V. elliptical or slightly constricted. L. 0,ii to 0,13; B. 

 0,04 7 to 0,0 6 mm. Central nodule large, quadrate, its horns almost parallel. Eurrows linear 



