96 p. T. CLEVE, SYNOPSIS OF NAVICULOID DIATOMS. 



space, half as broad as the valve and crossed by somewhat radiate rows of alveoli. Rows of alveoli 

 8 in 0,01 mm. Alveoli 8 in 0,oi mm. — Nav. microtatos Pant. I p. 27 PL IX f. 80. 



Marine: Szakol, Hungary, foss.! South Naparina, Trinidad, foss. (Deby Coll.)! 



Var. Christianii T. C. — L. O.045; B. 0,04 mm. Median rows of the alveoli at the margin 

 alternately longer and shorter, 11 in 0,oi mm. — Raphidodiscus Marylandica, Christianii and 

 Febigerii T. C. Microscope 1889, according to WoUe D. of N. Am. PL LXXXIV f. 1 to 4. Icon, 

 n. PL II f. 1. 



Marine: Cambridge, Maryland, fossil (Deby Coll.)! 



64. D. Smithii E^ts. (1856). — V. elliptical. L. 0,027 to 0,05; B. 0,oi5 to 0,o35 mm. 

 Central nodule small. Terminal nodules close to the ends. Furrows narrow, close to the horns. 

 Costse 7 to 11 in 0,i 1 mm. alternating with double rows of alveoli disposed in obliquely decussa- 

 ting lines, twice or more as close as the costse. — Nav. elliptica W. Sm. B. D. I p. 48 PL XVII 

 f. 152 a. N. Smithii Br^b. in W. Sm. B. D. II p. 92. iV. Smithii v. borealis f. minor Gtbun. Franz 

 Josephs Land D. PL I f. 41. N. SmitUi A. S. Atl. VII f. 16, 17. N. S. D. I f. 19.? N. Scutellum 

 V. H. Syn. PL IX f. 11.? Nav. Smithii var. Imvis Dannf. Baltic D. p. 30 PL II f. 15. 



Marine and brackish: Franz Josephs Land (Grun.), Spitzbergen! Sea of Kara! Finmark! 

 Baltic! Grulf of Bothnia! North Sea! Mediterranean Sea! Madagascar! Seychelles! Tasmania! Java! 

 New Zealand! Colon! Campeachy Bay! 



Nav. Doczyi (Pant. II p. 45 PL XIV f. 247, 1889) from Bremia in Hungary, seems to be 

 a finely costate variety of D. Smithii. Its length is 0,052 and its breadth 0,oi7 mm. The costse 

 are 14 to 16,5 in 0,oi mm. and are described as indistinctly punctate. 



65. D. sabovalis Cl. N. Sp. — V. elliptical. L. 0,38; B. 0,o]9 mm. Central nodule large, 

 rounded. Furrows narrow, closely following the central nodule and its horns. Costse 10 in 0,oi 

 mm., alternating with double rows of alveoli, forming oblique lines, about 18 in 0,oi mm. — 

 PL I f. 27. 



Fresh water: New Zeeland, Paeroa. 



This form resembles D. ovalis in its shape and large central nodule, but has the structure 

 of D. Smithii. 



66. D. borealis G-run. (1884). — V. elongate-elliptical. L. 0,65 to 0,o78; B. 0,025 to 0,o265 

 mm. Central nodule elongated. Furrows narrow, dilated around the central nodule and crossed by 

 costse, interrupted by a longitudinal band. Costse 10 in 0,oi mm., alternating with rows of alveoli, 

 forming oblique longitudinal lines, about 24 in 0,oi mm. — Nav. Smithii var. borealis Grun. 

 Franz Josephs Land D. p. 56 (4) PL I f. 40. Nav. fusca Donk. B. D. PL I f. 5.? 



Marine: Franz Josephs Land (Grun.), Matotschin Sharr, Sea of Kara! GuUmarefjord! Java 

 (var. L. 0,042; B. 0,oi7 mm. Costse 8 puncta 17 in 0,oi mm.). 



Var. subconstrieta Cl. — V. slightly constricted in the middle. L. 0,58; B. 0,02 mm. Costse 

 10, alveoli 24 in 0,oi mm. Furrows narrow, the costse not interrupted by a longitudinal band. 



Marine: Campeachy Bay! 



This form resembles D. vacillans, from which it differs by the alveoli forming oblique rows. 

 The fig. 14 and 15 PL VII in A. S. Atl. seem to belong to D. borealis. 



67. D. major Cl. N. Sp. — V. elliptical. L. 0,07 to 0,17; B. 0,o37 to 0,o6 mm. Central 

 nodule large, rounded quadrate. Terminal nodules distant from the ends. Furrows rather broad; 

 their outer margins enclosing a space 1/4 to 1/3 as broad as the valve, crossed by costse and double 

 rows of alveoli. Costse 5 to 7 in 0,oi mm. alternating with double rows of alveoli, 7 to 15 in 

 0,01 mm., forming oblique lines. — Nav. Smithii A. S. Atl. VII f. 19' (typical)! 22, 21 18 

 V. H. Syn. PL IX f. 12. Suppl. PL B. f. 23. 



Marine: North Sea! Marocco! Barcelona! Madagascar! Macassar Straits! Sumatra! China! 

 Japan! Australia! S:ta Monica, Calif, fossil! Colon! 



