154 p. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



41. N. (Libellus) aponina KtJTZ. (1836). — V. narrow, lanceolate, acute. L. 0,025; B. 0,oo4 

 mm. Axial and central areas indistinct. Striae about 30 in 0,oi mm. Connecting zone longitu- 

 dinally striate. — Brachysira aponina KtJTZ. Dec. N:o 153 (according to Lagst.). Nav. apon. Kt)TZ. 

 Bac. p. 91 PI. IV f. 1. V. H. Syn. PI. XII f. 15. Lagst. Of vers, af K. Sv. Vet.-Akad. FOrh. 

 1884 PI. X f. 8. Lihellus apon. Dk Toni Atti del R. Inst, de Scienz'e (ser. VII) VII p. 967. 



Hot springs: Abano (Italy). 



The above description is from the figure in V. H. Syn. as I have had no opportunity of 

 examining this species. 



42. N. (Libellus) Biilnheimii GtRUN. (1880). — V. linear-lanceolate, with rostrate to capitate 

 ends. L. 0,02; B. 0,oo3 mm. Areas indistinct. Striae parallel, 30 in 0,oi mm., the two median 

 stronger. — Grun. in V. H. Syn. p. 108 PI. XIV f. 6 a. 



Salines: »Sulzaj (Rabh. Alg. 1301)! 



Var. helgica Grun. — V. with somewhat obtuse ends. Connecting zone with fine, longitudinal 

 striffi (V. H. Types N:o 113). 

 Marine: Ostend. 



43. N. (Libellus) hamulifera Grun. (1880). — V. lanceolate, sometimes slightly asymme- 

 trical, with subacute ends. L. 0,o5i to 0,058; B. 0,012 to 0,oi4 mm. Median line with somewhat 

 approximate central pores. Its terminal fissures distinct, hook-shaped, turned in the same direction 

 and at some distance from the ends of the valve. Areas indistinct. Striae in the middle 19 to 21 

 in 0,01 mm. slightly radiate, at the ends 25 in 0,oi mm., parallel, punctate; puncta, about 20 in 

 0,01 mm., forming undulating longitudinal rows. — Grun. A. D. p. 44. Icon. n. PI. Ill f. 16, 17, 18. 



Marine: Mediterranean Sea (Grun.), Adriatic (Grun.), Sebastopol! Ceylon (Weissflog Coll.)! 

 Java! Barbados! 



Var. interrupta Cl. — L. 0,i; B. 0,02 mm. V. as in N. Lihellus. Striae interrupted on 

 each side of the median line by a narrow longitudinal area. Striae 20 to 21 in 0,oi mm. Puncta 

 23 in 0,01 mm. — PL III f. 19. 



Marine : Japan ! 



N. hamulifera closely resembles N. Lihellus and is characterized by its hook-shaped, terminal 

 fissures. 



44. N. (Libellus) plicata Done. (1873). — V linear, convex, with obtuse ends. L. 0,0 6 to 

 0,09; B. 0,012 to 0,016 mm. Terminal nodules close to the ends. Areas indistinct. Striae in the 

 middle 17 to 19 in 0,oi mm., almost transverse, at the ends 20 to 21 in O.oi mm., also transverse, 

 finely punctate, puncta about 18 in 0,oi mm. forming longitudinal, undulating rows. Frustule 

 in the zonal-view with fine, longitudinal striae on the connecting zone. — Donk. B. D. p. 59 PL IX 

 f. 2. Grun. A. D. p. 36. 



Marine: Kara Sea (Grun.), England! Scotland! Baltic (Grun.), Balearic Islands! Triest (Grun.), 

 Labuan! Brazil! 



Var. sumatrana Cl. — V. very convex with more acute ends. L. 0,i3 to 0,17; B. 0,017 to 

 to 0,02 mm. Axial area indistinct; central small, orbicular. Striae 15 (middle) to 16 (ends) in 

 0,01 mm. transverse throughout, coarsely punctate, puncta about 17 in 0,oi mm., forming un- 

 dulating longitudinal rows. — N. oxeia Castr. D. Challenger Exp. p. 31 PL XX f. 8 (1886)? 



Marine: Island of Muntok, Sumatra (Grove Coll.)! Java! 



45. N. Garkeana Grun. (1863). — V. linear, with obtuse ends. L. 0,04 to 0,09.5; B. O,oii to 

 O,oi.'i mm. Axial area indistinct; central very small, elongated. Striae 18 to 19 in 0,oi mm., 

 almost parallel, distinctly punctate; puncta about 20 in 0,oi mm., forming longitudinal rows. 

 Frustule in zonal-view arcuate, subrectangular, with broad connecting zone, on which are 2 to 4 

 rows of short striae (13 in 0,oi mm.). — Rhoiconeis Gar. Grun. Verb. 1863 p. 148 PL IV f. 12. 



Marine: Behrings Strait! Kamortha! California! North Pacific Ocean (Grun.). 



