BOTAMCAL GAZETTE. 27 S 



radical error, as it appears to us, in Caruel's disposition of the plants 

 of the class Thallodeai consists in making use of the asexual reproductive 

 bodies in characterizing the sub-classes. Conidia and zoospores at 

 least, and almost certainly the tretraspores also (chains of four co- 

 nidia ?),are homologues, whose differences are related to differences in 

 the habitat of the plants producing them. Conidia (if we except te- 

 traspores) are aerial, while proper zoospores are aquatic. 



The position assigned to the Characere is scarcely a tenable one. 

 They are too nearly related to the FloridiiB, and too distantly to the 

 ferns to warrant placing them between the Bryogama; and Prothallo- 

 gama?. 



The separation of the Phanerogamae into three classes will strike 

 every one as an innovation of doubtful value. Why the orthography 

 of Gymnospermaj should be changed to Gynosperm^e, is also to be 

 questioned. It will be observed that the cohorts and orders of the 

 Angiospermfti rank higher respectively than do the groups bearing 

 tliese names in the system most in vogue in this country: the families 

 (omitted for want of space) in Caruel's system, are almost the equiva- 

 lents of the orders of Bentham and Hooker, while Caruel's orders arc 

 nearly equivalent to Bentham and Hooker's cohorts. 



Division GYMNOGAM^. 

 Class Plasmoide^e. 

 Coiiort PInitmodiaUe. 

 Oriloi- Myxomycetes; Piim. Ccratiaccir', Trichiacea?. 



Class TlIAIXODEiE. 



Siib-clasB ScHizoapoRopHOK^. 

 Coiiort Schizo»porat<T . 

 Order N ob tochirtciv ; Fam. Chroococcaccic, Oscillariaccrp, Nostocacc.'O, Uiviilariaccn;, 

 Scylouemacoii'. 



Sub-rlase CoNiDiopnoRyE. 

 Cohort Gyinnosporaio'. 



Order Pnccin lde;v ; Fam. SporotrichacciP, FuearlaceiR, Stilbaccw, Tricliodcrmacoai 



I'HtilaKiiiacon', Puccinlacen'. 

 Order AgaricidciH ; Fam. Exobasidiaccic, Tremellaccre, Agaricaccre, Lycoperdonacea;. 



Cohort Angiogporafcp. 

 Order (t y m noasc i d e;r ; Fam. (•ymnonscacctr'. 



Order S p h;v> r i d ea> ; Fam. Ilolvcllace^p, Sphieriaceoe, Brysiphacea^ Tubcrace:w. 

 Order Lichcnidea'; Fam. Mvriangiacoip, Verrncariacea', Parmeliaccic. 



Sub-class ZoospoRonion/E. 

 Cohort Eiisoospora/.o'. 



Order Ulvidcu'; Fam. Cladoptkoracca-, Ulvacoa;, Sphacelariacea.', Sporoehuuceie. 



Cohort Zygosporalm. 

 Order Pandor i n id on' ; Fam. Hotrydiareie, Paiidorinace-.v, TTlotrichacoav 

 Order Zygncmidea'; Fam. Diatomace;c, Desmidiace;p, Zyg;nemaceiv. 

 Order Pcronosporldcif ; Fam. Mucoraceic, Chytridiace;e, Peronosporacca;, .Sapro- 



Icgniacea'. 



Cohort Ooxporafoe. 



Order V au ch eri dea' ; Fam. Monobicpharidaceiv, Volvocaceaj, \ aiicheriacea;, Sphaj- 



ropl('ace;e, (EdoKoniace:e, Coleocha'taeeiv. 

 Order Fiicideiv; Fam. Ectocarp ice;u, Fticaceiu. 



