474 dt:9cription ov [^Polygastrica. 



at the base, witli obscure interspaces ; stipes long, sub-dichotomons, 

 slender. Length l-310th. 



Rhtpidophoea mperha. — Larger, slender, and elegant ; bacilli in 

 pairs (geminate) or solitary, cuneiform ; slightly acute at the base ; 

 interspaces (pores) of a golden yellow colour, globose, loosely distri- 

 buted ; stipes filiform, long, dichotomous ; secondary branches short 

 and lateral. Length 1-3 10th. North Sea and Adriatic. 



R. Meneghiniana . — Large, bacilli geminate, oblong-cuneate ; apex 

 rather wide ; interstices scattered ; globular, brownish olive ; stalk 

 very long, with widely spreading dichotomous branches. Length 

 1 -288th. (P. 16, f. 19.) On Alg^, Venice. 



R. grandis. — Very large ; bacilli widely cuneate, with large, 

 globose, granular- looking interstices ; stalk very long, with filiform 

 dichotomous divisions. Venice. Length 1-1 20th. Var (l.Jarach- 

 noidea. The lateral bacilli mostly caduceous. Length 1-1 80th to 

 1-1 68th. Trieste. 



R. craticula (Montague.) — Shortly stiped ; stipes slender, dilated 

 at the base, sub-flabellate, craticulate ; bacilli, three to six, oblong- 

 lanceolate, truncate, and obtuse at each end. Length 1 -650th to 

 1 -450th ; wider at the centre than on each side, which is very 

 slightly attenuate. (Ann. d. Sciences, Nat., vol. 14, 1850, p. 308.) 



Genus Sceptroneis. — Attached (?) lorica of two equal, styliforra, 

 compressed valves, not concatenate ; cuneate, (when living, probably 

 pedicellate) ; a median longitudinal suture on the sides of each valve ; 

 no umbilicus. Has the habit of the genus Meridon, or of Gom- 

 phoncma, without the lateral umbilicus, and not concatenate. 



S. caduceiis. — Testule bacillar, long, wedge-shaped, with a round 

 turgid head, surmounting a slender neck ; turgid at the middle, with 

 granules disposed in rows, and glistening like jewels ; the entire 

 form being vciy beautiful; granules fifteen in 1-1 200th. Length 

 1-1 92nd, exceeding the width eighteen times. Bermuda. 



Genus Stkiatella, (Ehr.) — The zig-zag little standard. Lorica 

 square, tabular, or mostly longer than broad, and without a central 

 opening ; attached obli(iuely by a short lateral pedicle, or foot stalk, 

 and developed in the form of little banners, one end of which often 

 separates (gapes.) (See fig. 203.) 



Mr. llalfs thus defines Striatella : " Filaments attached by stipes, 



