Naviculacea.'] infusoktal animalctjles. 469 



more attenuated at the base, aucl they are about as broad as the 

 front, whereas in G. gcminatum they are much broader. 



GoMPHONEMA cristatum (Ralfs.) — Frustules crested, lateral surfaces 

 striated, obovate, not constricted beneath the apex ; viewed laterally 

 the crest appears like a terminal point. Found by Mr. Jenncr on Con- 

 ferva glomerata, near Shoreham, Sussex. It is very minute, the stipes 

 slender, simple, or rarely once divided. It resembles G. minutum, 

 (G. acuminatum, Ehr.) in its terminal crest, but is smaller, the frus- 

 tules shorter, and theii' angles rounded; the lateral view is also 

 broader, and wants the constriction below the apex. 



G. BerMeii (GrcviUe) = G. (?) oUvacea (Ehr.) 



G. minutissimum. Var. h. (Ralfs.) — This variety is more branched 

 than the ordinary plant, and the stride, extending the length of the 

 fi'ustule from the terminal pimcta, are more strongly marked. On 

 marine Algae. (P. 14, f. 9 and 12.) 



This species differs from the other in its curved frustules, in 

 having a notch on one only of the lateral margins, and two striae passing 

 do-«Ti the frustule, connecting the upper and lower puncta. Found at 

 Eastbourne, Sussex, and in Ireland. 



Q. paracloxum = Echinella (?) ixiradoxa (Ehr.) — Puncta at upper 

 end strongly marked, with a strioD from each passing down the 

 frustule ; lateral surfaces clavate, narrow, not striated. It forms a 

 brown, gelatinous covering on the smaller marine Algsc, but turns 

 green on drying. There arc no puncta on the lateral margins, and 

 no strife. 



Genus Odontella (Kiitz.) — Individuals smooth, rather round but 

 compressed, fasciate in the centre, furnished with two lateral horns 

 at each apex, concatenate, and attached. It is a member of the 

 fomily Biddulphiem, and all its specimens are marine. 



The genus bearing this name, in the system of Kiitzing, docs not 

 coiTCspond with that to which Ehrenberg has attached the same 

 appellation, but mainly represents the Denticella, whilst Odontella 

 (Ehr.) is a genus of Desmidiem (p. 292.) 



0. suhceqiia. — Segments quite smooth, oblong, lateral, horns minute, 

 with no middle process. Among Confervce, Heligoland. 



O. ohtusa. — Joints quite smooth, but shorter, with turgid, obtuse, 



