KONGL. SV. VET. AKAUEMIENS HANDLINGAR. BAND 27. N:0 3. 181 



stomosing with longitudinal costse, thus forming a net-work of quadrate alveoli. Lower V. with 

 indistinct axial area, small orbicular central area and 9 striee in 0,oi mm., composed of distinct 

 puncta, about 9 in 0,oi mm. — PI. Ill f. 6, 7. 

 Marine: Galapagos Islands! 



4. C. formosa Brdn (1891). — L. 0,075 to 0,i; B. 0,o5 to 0,o7 mm. Upper V. with narrow, 

 lanceolate axial area, and slightly radiate costse, 5 in 0,oi mm., anastomosing into a net-work of 

 rectangular alveoli, 4 in 0,oi mm. Lower V. with straight median line, and indistinct axial area. 

 Central area transverse, narrow lanceolate. Terminal areas small and near the margin. Strife 

 6,5 in 0,01 mm. slightly radiate, coarsely punctate (puncta 8 to 9 in 0,oi mm.) and ending with 

 double rows of puncta. — D. espfeces nouv. p. 16 PI. XVllI f. 6. Pant. Ill PL XXXII f. 457. 

 A. S. Atl. CXCIII, 42 to 47. 



Marine: Japan, fossil (Brun Coll.)! Indian Ocean (Brun), Wombats (Pant.). 



A peculiar form, the lower valve of which resembles C. costata, from which it differs by 

 the absence of a marginal annulus. There is also some resemblance to C. versicolor, but the upper 

 valves are entirely dissimilar. 



5. C. versicolor Brun (1891). — Elliptical. L. 0,05 to 0,o65; B. 0,035 to 0,o4 mm. Upper 

 V. with narrow, lanceolate axial area, and strongly radiate costee, 5,5 in 0,oi mm. Intercostal 

 spaces transversely lineate, lineolse 13 in 0,oi mm. Lower V. with straight median line reaching to 

 the margin. Axial area indistinct; central area narrow, transverse. Striae 7 in 0,oi mm. slightly 

 radiate, punctate; puncta 14 in 0,oi mm. Median striae shorter than the others. — T). especes 

 nouv. p. 19 PL XVIII f. 1. A. S. Atl. CXC f. 12 to 14. 



Marine: Japan, fossil (Brun Coll.)! Mogador (Brun). 



6. C. pinnata G-reg. (1859). — Elliptical. L. 0,o24 to 0,04; B. 0,oi9 to 0,o3 mm. Upper 

 V. with broad, axial area and strong, slightly radiate costse, 4 to 5 in 0,oi mm. Intercostal 

 spaces with double rows of puncta, arranged in oblique lines. Lower V. as in Cocc. pseudo- 

 marginata, but smaller and with closer striation (according to Grunow). — C. pinnata Greg. M. 

 J. VII p. 79 PL VI f. 1. V. H. Syn. PL XXX f. 6, 7. A. S. Atl. CLXXXIX f. 1 to 5. C. 

 Lorenziana Pbrag. D. de Villefranche PL V f. 38? G. denticulata Lbud. Fortm. D. de Ceylon 

 PL I f. 2? Ehaphoneis Archeri O'Meara Quek. M. J. Vol. VII ser. 2 PL VII f. 12? 



Marine: Spitsbergen! Finmark! North Sea! Mediterranean Sea! Adriatic! Seychelles! Island 

 of Bhea near Singapore! 



Pleuroneis Cl. N. G. 



Frustules with a marginal rim. Valves broadly elliptical to orbicular. Upper valve with 

 more or less narrow axial area and radiate costse, alternating with double rows of puncta, forming 

 oblique, decussating lines. Lower valves with radiate rows of finer puncta. 



1. €. britanniea N^geli (1849). — Broadly elliptical. L. 0,025 to 0,o5; B. 0,022 to 0,o37 

 mm. Upper V. with very narrow axial area. Costse 6 to 10 in 0,oi mm., alternating with double 

 rows of small puncta (about 18 in 0,oi mm.) forming oblique lines. Lower V. with distinct median 

 line, not reaching to the margin. Axial area indistinct. Central area very small and orbicular. 

 Strife about 10 in 0,oi mm. Rim with about 5 costse in 0,oi mm. — G. brit. KtJTZ. Sp. Alg. 

 p. 890. V. H. Syn. PL XXX f. 1, 2. G. coronafa Btw. M. J. VII p. 179 PL IX f 2? G.pseudo- 

 marginata Jan. Rab. Honduras D. PL I f. 16? C. scutelUformis Grun. in Cl. M. D. 148, 154, 208 

 —210. G. costata var. A. S. Atl. CLXXXIX f. 8? G. eximia A. S. Atl. CXCII f. 31? 



Marine: Mediterranean Sea! Adriatic (Grun.)! Barbados! . 



This species resembles, under a low power, G. Scutellum, from which it is however widely 

 different. G. Ningpoensis Petit (Mem. Soc. Cherbourg XXIII p. 207 PL I «, 1881) perhaps repre- 



