Ser. E,HODOSPERMEiE. Fam. CnjptonemiaceoR. 



Plate XCIII. 



GATTYA PINNELLA, Harv. 



Gen. Char. Frond distichous, pinnatifid, hollow, tubular, with a mem- 

 branous periphery, and an articulated, monosiphonous axile fila- 

 ment. Axile filament articulate, callithamnioid, emitting at each joint 

 whorled, dichotomous ramelH, whose tips, cohering together, form 

 the membraDous periphery of the frond. Fruit unknown. — Named 

 in honour of Mrs. Gatty, of Ecclesfield, Yorkshire, a diligent ex- 

 plorer of British Algae and marine animals, and author of 'A Horn- 

 book of Phycology,^ etc. etc. , 



i'rom disticha, jnntiatifida, tuhulosa (cava), peripherio rnembranaceo axique mo- 

 yiosiplionio artlculato coniposita. Filuiii centrale articidatum, callithamnio- 

 ideuni, ad genicula rmnellos vertlclllatos dichotomos emittens, quorum apicil/us 

 arete coh(srentihm periphnrium memhranacemu frondis condructimi est. 



Gattya pinnella, Harv. 



Gattya pinnella, Harv. in Trans. R. I. Acad. v. 22. p. 555 ; Jiff. Uxsic. 

 Austr. 11. 422. 



Hab. Parasitical on Alga3 and CoraUines, Eottnest Island, W. H. H. 



Geogr. Distr. Western Austraha. 



Desck. Fronds rising from prostrate surculi, which are closely attached at inter- 

 vals by minute discs to the surface of some Alga, afterwards free and erect, 

 1-1|^ inch high, alternately or irregularly branched. The branches are per- 

 fectly distichous, of unequal lengths, long and short occurring together, and 

 all are linear in outline and deeply pinnatifid. Pinnules alternate, \ a line 

 long, patent, broadly subulate, subacute, with blunt axils. Tiie whole 

 frond is tubular and hollow, but compressed, a cross section being nearly 

 oval. The tube is traversed by a jointed, monosiphonous, coloured, filamen- 

 tous axis, resembling the branch of a Callithamnion ; this axis, at each joint, 

 throws out a whorl of repeatedly dichotomous, horizontal, fastigiate ru- 

 melli, whose extremitica alone anastomose, and thus form the enveloping 

 membrane which constitutes the membrarjous covering of the frond. The 

 whole frond is therefore coraposerl of the axis and its appendages. When 

 viewed under a low magnifying power (as Fig. 2), the frond appears as if 

 midribbed and penninerved ; this appearance vanishes under an increased 

 power, and is caused by the axile filament and its ramelli being seen 

 through the semitranslucent cellnles of the peripheric membrane. 'No fruc- 

 tification has yet been observed. The colour is a dark, somewhat brownish 

 red. The substance is soft, but not gelatinous, and the plant adheres firmly 

 to paper in drying. 



