OF THE NAVICULE^. 



925 



lanceolate, with subacute apices and 8 to 

 30 loculi ; stride 42 in -001". SD. ii. p. 64, 

 pi. 54. f. 340. Brackish water. Britain. 



M. Smithii (Thw.). — Valves oblong- 

 lanceolate, with produced, obtuse or 

 capitate apices, and 6 to 24 loculi ; striae 

 42 in -001". SD. ii. p. 65, pi. 54. f. 341. 

 Fresh or brackish water. Britain. 



M. apiculata (S.). — Valves elliptic- 

 lanceolate, Avith slightly produced, ob- 

 tuse, conic apices, and 30 to 50 loculi ; 



striae 42 in -001' 

 f. 387. Marine. 



. SD. u. p. 

 Britain. 



65, pi. 62. 



M. GrevUlii (S.). — Valves linear, Tvdth 

 obtuse, cuneate ends, and 15 to 20 loculi ; 

 striae moniliform, 24 in 001. SD. ii. 

 p. 65, pi. 62. f. 389. Fresh water. Britain. 



M. minuta (Grev.). — Valve elliptic- 

 lanceolate or elliptic-oval, conspicuously 

 apiculate ; loculi 12 to 18 ; striae very fine 

 and close. Trinidad. Grev. MJ. v. p. 12, 

 pi. 3. f. 10. It is a species evidently aUied 

 to 31. apiculata, but differs in being 

 scarcely half the size, and essentially in 

 the much larger loculi j it is also much 

 more apiculate. 



Genus PHL YCT^:N'IA (Kiitz.). — Frustules navicular, included in (globose) 

 gelatinous cells. Maiine. 



Phlyct^nia minuta (K.). — Parasitic ; 

 cells hyaline, achromatic, solitary, scat- 

 tered, or binately approximate and aggre- 

 gated; included naviculae few, binately 

 or quatemately conjoined, smooth ; 

 front view linear, with truncate apices ; 

 valves broadly lanceolate, with acumi- 

 nated ends. KSA. p. 96. Adriatic Sea. 



P. maritima (E., K.). — Naviculae 



smooth (?), linear, with rounded ends 

 contained in distinct, but contiguous, 

 gelatinous cells. KA. p. 96. = Fnfsfulia 

 maritima, E Inf. p. 232. Near Gothen- 

 burg. 1-1200" to 1-1150". This species 

 occurs as a brownish jeUy-like mass on 

 stones. In the gelatinous cells Ehr- 

 enberg obseiTed from one to twenty 

 frustules. 



Genus DICKIEIA (Berkeley). — Frond subgelatinous, plane, attenuated to- 

 wards the base, containing scattered, navicular, imperfectly silicious frustules. 

 Marine. Dickieia is distinguished by its plane frond and scattered frustules. 



DiCKiEiA ulvoides (Berk.). — Frond 

 undivided ; valves elliptical. ANH. xiv. 

 pi. 9; SBD. ii. p. 66, pi. 54. f. 342. 

 Britain, (xv. 31.) Frond linear or 

 obovate-stipitate ; striae obscure, 36 in 



'001" ; nodule transverse, Sm. 



D. pinnata (Ralfs). — Frond divided ; 

 valves elliptic-lanceolate. ANH. 2nd 

 ser. viii. pi. 5._ f 6; SBD. ii. p. 66, pi. 54. 

 f 343. Britain. Autumn. Divisions of 

 frond subpinnate; striae obscure, 40 in 

 ■001" ; nodule pimctifomi, Sm. 



Genus RHAPHIDOGLCEA (Kiitz.).— Frond globose, gelatinous, tender, 

 filled with fusiform bundles of naviculae disposed in radiating threads. 

 Marine. '' The principal character of this genus is taken from the amor- 

 phous disposition of the gelatinous substance in which the frustules are 

 immersed. The frustules are mixed together in a disorderly manner in 

 Berkeleya, whilst in Ehaphidogloea they are arranged in fusiform fascise, 

 confluent by the pointed extremities" (Meneg.). We think this genus 

 might, without inconvenience, be united with Berkeleya. 



Rhaphidoglcea medusina (K.). — 

 Minute ; fascicles lanceolate-acuminate, 

 in irregular, reticulately-branched, con- 



tinuous, radiating threads ; naviculae 

 lanceolate. KB. p. 110, pi. 22. f. 7. Me- 

 diterranean Sea. 1-600". 



it. manipidata (K.). — Globose, pisi- 

 form; rays of fascicles reticulated, not 

 interrupted; naidculae linear-lanceolate, 

 obtuse. KB. p. 110, pi. 22. £ 5. Eui-ope. 

 1-700" to 1-290". 



K. interrupta (K.). — Pisiform, with 

 slender rays of fascicles, interrupted in 

 a joint-like manner, with gradually ta- 

 pering branches; naAacidae linear, slightly 



attenuated at the truncate apices. KB. 

 p. 110, pi. 22. f 6. Adriatic Sea. 1-300". 

 R. micans (Lyngb., K.). — Subglobose ; 

 rays of the larger fascicles irregular, 

 obsolete ; navicidae linear - lanceolate, 

 subulate, rather acute, elongated. KB. 

 p. 110, pi. 22. f. 8. = Schizonema micans, 

 AD. p. 17 ; Naimema micans, E Inf. ; 

 Frustulia costata, LobarzeuskyinLinnaea, 

 1840, pi. 5. f. 1. Europe. " Mr. Tuffeii 

 West informs us that, from careful obser- 

 vation of li\aug specimens, he is satisfied 

 that this species is identical with Am- 

 pliipleura pellucida, in which opinion the 

 late Prof Smith fidly concurred. 



