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



To this group of forms belongs probably I), oruata {Nav. ornata A. S. Atl. LXIX f. 5. 

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

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

 have hitherto not seen any uninjured specimen. 



C Forms with hroad hinulce. 



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

 ments. L. 0,o'.i to 0,2 1 ; B. 0,03 to 0,o6; at the constriction 0,oi8 mm. Lunuke very broad. 

 CostcK 4 to 5 in 0,oi mm. — Nav. nmltkostata GtRUN. Verb. I860 p. 524 PI. Ill 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. PI. I f. 5, 6 II f. 4 (corroded). Nar. 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! Labiian! 

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

 Hungary! Moravian Tegel! Oran (Atl.), J^^gina (Atl.), Nankoori! S:ta Monica Cal. 



Var. nanlxoorcnsis GtRUN. (1881). — V. less constricted, with cuneate ends. L. 0, i 2 ; B. 0,o53; 

 at the constriction 0,042 mm. Costte 4,5 in 0,oi mm. — Nav. Crahro var. nanJiOor. A. S. Atl. 

 LXIX f. 4 (corroded). 



Marine: Nankoori, fossil (Atl.). 



Var. O'Mcari (tRUN. Ms. — V. elliptical, not constricted. L. 0, is.i; B. 0,o58 mm. Lunulfe 

 very broad. Costfe parallel, 4 in 0,oi mm. — PI. II f. 12. 



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



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

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

 having, as it has, veiy broad luniila', filling almost the whole valve. L. 0,09; B. 0,o3 mm. 

 CostcE 6 in 0,0 1 mm. 



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

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

 0,0 1 mm. — Nav. Gihelii A. S. Probet. f. 13 PI. XII f. 73. 



Marine: Campeachy Bay (Atl.). 



Var. minuta Cl. — L. 0,o5 6; B. 0,024; at the constr. 0,oi6 mm. CostcC 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 0,012 mm. Costte 8 in 0,oi 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,oo7r) mm. 

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



Marine: Campeachy Bay (Atl.). 



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

 L. 0,076 to 0,13; B. 0,024 to 0,038; at the constriction 0,012 to 0,015 mm. LunuhB large, lunate. 

 Costffi 4 to 6 ill 0,01 mm Ocelli not distinct. — Nao. DirJi. 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. 

 suspjcda is to var. separahili.s. Dipl. coarctata may be a corroded Dirhombus, which however 

 am unable to decide, not having had an opjiortnnity 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 0,06 mm. Central uodule large, quadrate, its horns almost parallel. Furrows linear. 



