KONGL. SV. VET. AKADEMIEN8 HANDLINGAR. BAND 26. N:0 2. 65 



are visible. Striee 8 to 9 in 0,oi mm. smooth, slightly radiate. — Nav. Tcryoph. Cl. Vega p. 473 

 PL XXXVII f. 43. Var.? gelida Cl. 1. c. f. 42. 



Marine: North Siberian Sea, Cape Wankarema! Ice from the east-coast of Greenland ! 



A very peculiar form, for which I can find no other natural place than this. The large 

 lateral areas give this form some resemblance to N. Hennedyi, but nevertheless it cannot belong 

 to the section Lyratse of Navicula, as the structure of the strise is entirely different. If this 

 species really be a Caloneis, we have here the »lateral lines» in an extraordinary degree of 

 development. 



66. C. Musca Greg. (1857). — V. broad, pandurifbrm, with cuneate or rounded ends. L. 0,04 

 to 0,07; B. 0,016 to 0,025 mm. Axial and central areas united in a broad lanceolate, space, 

 sometimes constricted in the middle. Median line bordered by thick siliceous strings, with in- 

 distinct terminal fissures and approximate central pores. Strise 7 to 8 in 0,oi mm., smooth, or 

 more or less obsciirely punctate. Longitudinal line broad, submarginal. — Nav. Musca Greg. D. 

 of Clyde p. 479 PL IX f. 6. A. S. N. S. D. p. 86 PL I f. 15. AtL CLX f. 1, 2, 10, 11, 12. 

 Nav. constricta Grxjn. Verb. 1860 p, 535 PL III f. 18 (very bad). Nav. intercedens A. S. AtL 

 CLX f. 3, 4, 5. Nav. muscwformis Pant. Ill PL XVII f. 256 (1893). 



Marine: North Sea! Mediterranean Sea! Adriatic! Bab el mandeb! Ceylon! Seychelles! 

 China! Japan! Galapagos Islands! Porto Seguro! "West Indies! 



Var. intermedia Cl. — Strongly constricted, with elliptical segments. L. 0,o6 to 0,09; 

 B. 0,025 to 0,028 mm. Axial area narrow, lanceolate. Strise 6 in 0,oi mm. Longitudinal lines 

 broad, submarginal. — Nav. Musca var. intermedia A. S. AtL CLX f. 7, 8. 



Marine: Sumbava (Kinker Coll.)! Manila (Deby Coll.)! Samoa (AtL). 



Var. mirabilis Leud. Fortm. (1879). — V. panduriform with tongue-shaped segments. L. 0,077; 

 B. 0,029 mm. Axial area narrow linear, slightly dilated around the central nodule. Striee 7 (6 

 according to Leud.) in 0,oi mm. Longitudinal lines broad, submarginal. — Nav. mirabilis Leud. 

 Forth. D. de Ceylan p. 31 PL II f. 21. A. S. AtL CLX f. 6. 



Marine: Ceylon! Sumbava (Kinker Coll.)! Manila (Deby Coll.)! Sumatra! 



Var. eurynota Cl. — V. strongly constricted in the middle with elliptical segments. L. 0,0 8; 

 B. 0,02 (max.) to O.oi (min.) mm. Axial area very large. Strise 6 in 0,oi mm. Longitudinal 

 line narrow, median. — PL VI f. 9 (Part II PL I f. 9). 



Marine: Rio Janeiro (Deby Coll.)! 



Var.? margino-punctata Grove a. Sturt (1887). — V. slightly constricted in the middle, 

 with cuneate or rounded ends. L. 0,055 to 0,ii; B. 0,022 to 0,032 mm. Area broad and large. 

 Striae 10 in 0,oi mm., becoming faint towards the area. Longitudinal lines marginal.' — Nav. 

 margino-punctata Gr. a. Sturt Journ.Quek. M. Club. Ill (2) p. 132 PL X f. 7. Nav. margino- 

 lineata Gr. a. Sturt. 1. c. f. 11. A. S. AtL CLX f. 27. 



Marine: Oamaru, New Zealand, fossil! 



N Musca is extremely variable and many of the varieties are very dissimilar in ap- 

 pearance, but there exist, so far as I can find, no characteristics of sufficient importance for their 

 distinction as species. Nearly akin to N. Musca is also the following, which is described as a 

 species, because it occurs in many different places with the same characteristics. 



67. C. Kinkeriana Truan (1892). — V. panduriform, of the same outline as Diploneis Kiit- 

 zingii. L. 0,ii to 0,i3; B. 0,04 (max.) to 0,018 (min.). Axial area broad, with rudimentary 

 continuations of the strise. Median line straight, enclosed between thick siliceous strings, ^vith 

 small terminal nodules and approximate central pores. Strise 7 in 0,oi mm., smooth, or indistinctly 

 granulate, radiate. Longitudinal bands narrow, nearer to the margin than to the median line. — 



K. Sv. Vet, Akademiena Hamdlingav. Bd 26. N:o 2. 9* 



