492 T>T;i5Ci?TPTioN OF [^Polygasfrica. 



Length of fi'ust;;le l-132nfl to 1 -120th. On Algae, Trieste, Venixje, 

 and English and French Coasts (P. 16, f. 20.) 

 LiCMOPHORA radians = Echinella flabellata (Ehr.) 

 L. faheUata = Ecliinella splendida (Ehr.) 



L. Menegliiniana. — Frustules slender, very long, linear-cuneate ; 

 those terminal on the stipes, radiating ; the lateral ones scattered ; 

 stipes elongated, sub-divided. Length l-84th to l-72nd. Dalmatian 

 Coast, Adriatic Sea. 



L. divisa. — Frustules long, cuneate, sub-solitary or geminate (not 

 flabellate), acute at the base ; stipes short, weak, subdivided. Length 

 l-240th to l-180th. On Polysiphonia in the Adriatic (P. 16. f. 16.) 

 Genus Liostephania. — Orbicular, not concatenate ; testa bivalve, 

 its disc not perforated ; no internal septa ; valves equal (?), smooth 

 both at their centre and border, but with a crown of often strong 

 rays encircling the smooth centre. (This genus is misplaced. E,ead 

 as in sub-sec. 1.) 



L. Rotula, with six to fourteen simple rays. 



L. comta, with 6 to 13 rays, conjoined above by a circlet of puncta. 

 L. magnifica, with twelve rays, a pair of minute rays below, and 

 piincta interposed above. 



Genu^ MicEoiiEGA. — The generic description of Kiitzing is sub- 

 stituted for that given by Ehrenberg, as more clearly expressive of 

 the organisms in question. The species are also from Kiitzing. Com- 

 pound frond filiform, branched, enclosed by a common external tube, 

 and consisting of rows of navicular bodies. The rows of naviculae 

 are solitary, and are themselves severally enveloped by smaller, 

 special, secondary' tubes, or by curved and very slender fibres. 



This genus is nearly allied to Schizonema, and one species of the 

 latter, as described by Ehi-cnberg, is included by Kiitzing in this. 

 * Forms more slender and delicate. 



M. intricatum. — Delicate, slightly gelatinous, nebulose, of a pale 

 yellow lustre ; finely and irregularly branched ; branches spreading, 

 short, and obtuse ; rows of naviculae loose, interwoven with very 

 slender longitudinal fibres ; naviculae oblong, obtuse, truncate, very 

 small. Length l-1680th to l-1440th. Length of entire frond half 

 to one inch. Sidmouth, Dorsetshire. 



