OF THE CYMBELLE^. 



885 



transverse striae in -001" ; dorsum with 

 longitudinal series of short strine. GDC. 

 p. 49, pi. 5. f. 86. Scotland. 



A. arenaria (Donkin). — Frustules hj^a- 

 line, broadly linear, with rounded angles 

 and slightly gibbous middle ; outer com- 

 partment of valves canoe-shaped; dorsum 

 faintly marked with longitudinal lines. 

 Donkin, TMS. vi. p. 31, pi. 3. f. 16. 

 Marine. Northimiberland. Large; trans- 

 verse striae obscm-e. 



A. ampkioxys (Bailey). — Frustules 

 linear, with subtruncate apices ; lateral 

 view arcuate, finely striated, with convex 

 dorsum, concave venter, and rostellate 

 recurved extremities. BMO. p. 39, pi. 2. 

 f. 20-22. United States. The side view 

 bears a striking resemblance to Eunotia 

 amphioxijs, Bailey. 



A. hiseriata (Greg.). — Frustules elon- 

 gated linear, with rounded apices ; 

 median line marginal, except at the 

 centre, where it curves inwards ; dorsum 

 with longitudinal series of coarse trans- 

 verse striae. Greg. TM. v. p. 71, pi. 1. 

 f. 32. Scotland. Large, 



A. tenera (S.). — Frustides narrow 

 linear, with roimded or truncate ends ; 

 valve longitudinally rugose ; striae ob- 

 scure, 62 in -001". SBD. i. p. 20, pi. 30. 

 f. 252. Marine. England. Scarcely 

 silicious. Professor Smith regarded this 

 species as the ^4. lineolata, E., — an opinion 

 in which we are unable to concur, since 

 its narrow-linear form is very unlike the 

 broad inflated figm-e of the latter, and 

 could never be described as turgid. 



A. hacillaris (Greg.). — Frustules nar- 

 row linear, with slightly attenuated, ob- 

 tuse ends, outer portions very narrow, 

 arcuate, finely striated; dorsum with 

 longitudinal series of granides. GDC. 

 p. 55, pi. 6. f. 100. Scotland. Distin- 

 guished from A. pusilla by its finer striae 

 and g-ranules, Greg. 



A. pusilla (Greg.). — Frustules narrow 

 linear, with subtruncate apices ; outer 

 portions very narrow, canoe-shaped, 

 with 24 conspicuous striae in -001" ; 

 dorsum with longitudinal series of gra- 

 nules or short striae. GDC. p. 53, pi. 6. 

 f. 95. Scotland. 



A. Ercbi (E.). — Lateral view arcuate, 

 with obtuse apices, concave venter, and 



about 25 very fine striae in 1-1200". 

 ERBA. 1853, p. 526 ; EM. pi. 35 a. 23. 

 f. 3. Assistance Bay, North Pole. 



A. crystaUma(^.). — Frustides smooth, 

 crystalline, with convex dorsum, concave 

 venter, and broadlv truncate ends. 

 ERBA. 1840, p. 10. 'Tjorn. 1-432". 



A.fasciata (E.). — Frustules with con- 

 vex dorsum, plane venter, broadly trun- 

 cate ends, and longitudinal series of 

 closely set, fine striae. ERBA. 1840, 

 p. 11. Tjorn. 1-456". 



A. carinata (E,). — Frustules large, 

 navicular, with plane sides, acute apices, 

 and four lateral sti-iated fasciae. ERBA. 

 1840, p. 10. Island of Tjorn. 1-240". 



A. Atomus (E.). — Very minute, on 

 one side elliptic with rounded ends, on 

 the other linear and trimcate. 1-2640". 



A. JEgcea (E.). — Frustules navicular, 

 oblong, truncate, with 10 punctated 

 longitudinal lines, oblong umbilici, and 

 cm-ved lines; the space between the 

 umbilici Vvdthi two straight lines curved 

 at each end. ERBA. 1858, p. 13. 

 ^Egean Sea. 



A. stauroptera (Bailey). — Frustules 

 elliptical, elongated, ^dth striated mar- 

 gins ; central portions crossed, as in 

 Staiu-optera, by a broad band. BC. vii. 

 p. 8, f. 14, 15. Halifax, Nova Scotia. The 

 figure is elongated, acutely lanceolate, 

 and the nodules connected by a trans- 

 verse central depression. 



Species, the descriptions of which are 

 unknown to us. 



A. cymhiformis, EM. pi. 16. 1. f. 48. 



Lateral view semilunate, with convex 

 dorsum, straight venter, obtuse apices, 

 diverging striae, and submarginal sutural 

 line and nodule. 



A. gigas,^ EM. pi. 6. 2. f. 13. North 

 Africa. Figm'e imperfect, large, oval, 

 transversely striated ; connecting zone 

 with faint longitudinal lines. 



A. incurva, Greg. MJ. iii. pi. 4. f. 5. 

 Scotland. Lateral portion canoe-shaped 

 and finely striated. 



A. paradoxa (E.), A. vulgaris (E.), 

 Asia ; A. Nilotica (E.), River Nile ; A. 

 ocellata (E.), Florida. 



Genus RHIZONOTIA (E.). — Frustules with two median nodules (with 

 the character and form of Amphora), but by longitudinal division often 

 becoming a mass united together in a longitudinal series by a progeny of 

 stolons or silicious radicles. This form is adnate on Confervae, and has many 

 fine longitudinal strise, which appear somewhat rough or granular. The 



