194 V. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



Var. Kurzii GrRUN. (1878). — V. rhombic-lanceolate, with rounded ends. L. 0,09 to 0,105; 

 B. 0,0 3 6 mm. Median line strongly excentric. Axial area semilanceolate, unilateral. Alveoli dis- 

 posed in oblique rows, crossing each other in an angle of about 80°, and about 7 in 0,oi mm. 

 Transverse costee marginal, 10 — 11 in 0,oi mm. — Nav. {Alloioneis?) Kurzii Grun. in CI. West 

 Ind. D. p. 8 PI. II f. 12. 



Brackish water: Elephant Point, India (Grun.), Singapore! Sumatra (Grove Coll.)! 



8. T. velata A. S. (1876). — V. lanceolate, gradually tapering to the obtuse ends. L. 0,o7 

 to 0,13; B. 0,02 to 0,022 mm. Axial area very narrow or unilateral; central area small, rounded. 

 Alveoli rectangvilar, disposed in irregular, oblique rows and in transverse rows; the latter almost 

 parallel or slightly radiate at the ends, 15 — 16 in 0,oi mm. Fine longitudinal strise 25 in 0,oi 

 mm. — Nav. velata A. S. Atl. PL XL VIII f. 33—34; f. 35—37 (ho name). Nav. australis Petit 

 Cape Horn p. 125 (1888). 



Marine: Cape Good Hope (Atl.), Madagascar! Mauritius! Ceylon! King Georges Sound (Grove 

 Coll.)! Sumatra! Java! China! Japan! Sandwich Islands! New Caledonia! Cape Horn (Petit). 



Additional. 



Under the name Navicula Paludinarum Pantocsek has recently figured an apparently very 

 curious form, which ought perhaps to be included in a proper genus. The valve is lanceolate, 

 obtuse. L. 0,11.5; B. 0,038 mm. Axial area moderately broad, slightly dilated in the middle. 

 Striee costate, 8 in 0,oi mm., radiate throughout and alternating with single rows of large ocelli (?) 

 - Pant. Ill PL IX f. 144. Var. gracilior 1. c. PL XI f. 186. Fresh water? ))Bodos» (Pant.). 



Having had no opportunity of examining this remarkable form I am unable to decide as to 

 its place in the system. 



Mastoneis Cl. N. Gen. 



Valve with double structure. The exterior stratum with transverse strise, composed of 

 puncta; the interior with transverse costse, directed from the margin, where they are thicker, 

 towards the median line. 



The only known species has been placed by Geevillb and Grunow in the genus Stauroneis, 

 but it has no close relation to any species of that genus, and the peculiar structure of the valve 

 makes it advisable to form for it a new genus. I am unable to point out any close relation be- 

 tween this form and any other, although its general appearance has some resemblance to some 

 Mastogloiee. 



1. M. biforinis Grun. (1863). — V. elliptical with rostrate extremities. L. 0,o8 to 0,09; 

 B. 0,032 to 0,035 mm. Median lines with approximate median pores and small terminal fissures, 

 turned in the same direction. Central nodule transversely dilated into a very short stauros. No 

 axial area. Striee slightly radiate, 15 (middle) to 18 (ends) in 0,oi mm. punctate; puncta about 20 

 in 0,0) mm. Costse 8 — 9 in 0,oi mm. — Stauroneis hiformis Grun. Verb. 1863 p. 154 PL IV f. 7. 

 Staiironeis australis Grev. Ed. N. Ph. J. V. XVIII p. 187 f. 13 1863. 



Marine: Queensland (Grev.), Red Sea (Kinker Coll.)! Port Jackson! Labuan! 



