494 



CLEVE,-' DIATOMS. 



Ilasfogloia acuta Grun. in litt. — Lanceolate, with produced 

 ends. Rows of lociili at a little distance from the margin; 

 loculi larger in the middle than near the ends. Striae parallel, 

 very fine (not counted) punctate, puncta forming longitudinal 

 lines. Length 0,04 mm. Breadth 0,oi5 mm. — PI. 35, fig. 8. 



Mr. Grunow sent me some years ago a sketch of a new 

 Mastogloia, called acuta, which resembles this form so much 

 that I suppose they are identical. The M. acuta Grun. has 

 the loculi more separate from the margins than the Labuan- 

 specimens and the fine striae (30 in 0,oi mm.) more radiant. 



M. laminaris (Ehrb.) Grun. — Lanceolate, wdth produced 

 ends. Loculi large, 4 V2 in 0,oi mm. marginal. Strire fine, 20 

 — 24 in 0,01 mm., not interrupted, reaching the median line. 

 Length 0,03 mm. Breadth 0,oi mm. 



The determination is made by the aid of a sketch kindly 

 sent me by Mr. Grunow, who supposes, with some doubts, that 

 it may be the Ceratoneis laminaris Ehrb. It has been distrib- 

 uted in CI. & Moll. Diat. No 153 (Corsica). I have found 

 the same species in gatherings from the Adriatic Sea. 



31. undulata Grun. (Verb. 1860, pag. 576, PI. I, fig. 5. T. 

 M. S. 1877, pag. 176, PI. CXCV, fig. 5). 



M. rJiomhica CI. N. Sp. — Rhombic. Med. line slightly undu- 

 late, without accompanying lines. Striae coarse 11 in 0,oi mm. 

 slightly radiant, composed of distinct pearl-like puncta, which 

 form wavy longitudinal rows. Loculi marginal, equal in size, 

 about 6 in 0,oi mm. Surface of the valve not perfectly plane, 

 being a little impressed on both sides of the median line. 

 Length 0,048 mm. Breadth 0,02 mm. — PI. 35, fig. 9. 



M. lanceolata Thw. (Van Heurck Syn. PL IV, fig. 15—17). 

 Length of the valve 0,048 mm. Breadth 0,oi5 mm. Striae 16 — 

 19 in 0,01 mm. Loculi 6 in 0,oi mm. 



M. apiculata W. Sm. (Syn. II, pag. 65, PI. LXII, fig. 387). 



M. minuta Grev. — var. Avith 16 striae and 8 loculi in 0,oi 

 mm. Length 0,03 — 0,04 mm. Breadth 0,oi4 mm. — According 

 to Grunow (T. M. S. 1877, pag. 176) M. minuta has closer 

 striae, 25 in 0,oi-mm. 



M. JelinecJdi Grun. (T. M. S. 1877, pag. 174, PL CXCV, 

 fig. 1) var. Length 0,06 mm. Breadth 0,oi5 mm. Stria? 18 in 

 0,01 mm. Loculi 5 in 0,oi mm. 



M. qiiinque-costata (xrun. (Verb. 1860, pag. 578, PL VII, fig. 

 8) Several varieties. On a small specimen, 0,o3 mm. in length 

 and 0,018 mm. in breadth, I counted 26 striae and 4 loculi in 



