188 MR. C. EEID AXD MR. J. GROTES OX THE [vol. Ixxvii, 



\iU'. ELLIPSOIDEA. Oogoniuiu elliiDSoideuiii, sursum et cleorsiini 

 jDaiilo fastigatum. (PL \, fig. 10.) 



Var. BiTRrxcATA. Oogonium bitruncato-ellipsoideum, non- 

 uunquam ad basem paulo fastigatum ; foramen basilare diametro 

 medio. (PI. A\ fig. 18.) 



^The type varies in size and shape, the specimen fio:ured being 

 the largest and most distinctive. The variety ell/jjsoidea differs 

 fi'om it in being somewhat tapered at both ends, sHghtlv more 

 below than above; the variety hitruncata. on the other hand, 

 has usually both ends somewhat ti'uncate. 



The type and the variety ellipsoidea were obtained from the 

 Limestone-Band, only two specimens of the latter being found; 

 the variety hitruncata ^vas obtained in fair quantity froiu the 

 Eodent-Bed, and a single specimen fi'om the Basement (Seed) -Bed. 



10. Chara TrRBiXATA, sp. nov. (PI. VI, fig. 1.) 



Oogonium obovoideum, apiee insigne complanato, ad basem 

 ti-uneatam fastigatum, long. c. 625-650 p, crass, c. 100—1:50 ^, 

 cellulse spirales lat. c. 65 /x, plerumque complanatse ad apicem 

 €t basem dilatse, convolutiones novem— decem exhibentes ; foramen 

 basilare latum, margine angulis jDrar-tendentibus. 



A distinct-looking type, pale yellowish-brown, usually tapering 

 -decidedly towards the base. 



Limestone-Band, a few specimens only. 



11. TOLTPELLA HEADOXEysls, sp. UOV. (PI. YI. figS. 2 e\: 3.) 



Oogonium subglobosum ad basem levissime fastigatum, long, 

 €. 450^75 fj, crass. 400-425 /.* ; cellulse spii-ales lat. c. 60 fj.. crass, 

 c. 40ju,ad apicem turgid?p, convolutiones novem-decem exhibentes ; 

 foramen basilare parvulum, margine prominente. 



Fruits buff-coloured, with regular spii-al cells, somewhat 

 resembling in shape those of the living s^Decies T. prolifera, but 

 more globose, and having the tijDS of the spiral cells swollen, im- 

 plying a deciduous coronula. The concavity of the spiral cells in 

 this and the following species corresponds with what is usually 

 •seen in the di-ied fruits of the two living British species which 

 secrete a lime-shell. 



Obtained in fair quantity from the Eodent-Bed. 



12. TOLTPELLA PARVULA, Sp. nOV. (PI. YI, figS. 4 & 5.) 



Oogonium globoso-obovoideum ad basem subacutam paulo 

 fastigatum, long. c. 325-375 /./, crass, c. 225-275 /^ : cellulae 

 spirales concavse, lat, c, 40 ^, crass, c. 30 /x, ad apicem baud aut 

 leviter dilata?, convolutiones novem-undecim exhibentes ; foramen 

 iDasilare parvulum. margine prominente. 



Fruits cream- or buff-coloured, differing in size and shape from 



