^o^'] PROCEEDINGS OF THE NATIONAL MUSEUM. 109 



III the li^iit of these. <l;it;i, it l>ecoiiies possible lo sepiiratc our fossils 

 iii(o two jn'ioiips. Nos. S, !), l(i, 17, iiiid .")(» aic, costiite tliioii^hoiit jiiid 

 show siiij;le terminations of the rainiili. Their adinities are thus clearly 

 witli iniliserin aiid they must, therelbre, be refei'red to the genus 

 HalhcriU'H. Nos. 18, H), and '20 ar(i not costate and the terminations 

 of the rainuli ari; <listinetly bifid. Tlieir affinities are with IHctyota .uid 

 they consequently should bo referred to a related genus. 



Hrongniait* formerly referred a large number of fossils of diverse 

 ch;iract(U" to the genus Fiivoides, some of which he brought under the 

 division JHcti/otitcN from the general resemblance they bore to IHctyota. 

 These have since been variously distributed among different genera, so 

 that the name Dicti/otites has lost its function, ;ind so far as I am 

 aware it is now altogether obsolete. It therefore seems admissible to 

 reintroduce the name? as a, generic one, under wiiicli specimens 18, 19, 

 and 20 may be described. 



Haliserite.3 Dechenianus (Jr)])]). I'l. \, Fig. 6. 



This species is rei)resented in No. 17 by an imperfect plant answer- 

 ing to the following: 



l^'roiid dichotonious; divisions linear .'>. 5""" wide; angle of divergence 

 40'^; midrib prominent thnuighout, margin wavy. 



The specimen shows no normal terminations of any of the ultimate 

 divisions, but its general charactei-istics are otherwise so well defined 

 that it is quite safe to refer it to the above s])e(!ies. Mr. Prosser informs 

 nie tliat this fossil was identified by Lescpu'reux; as a fruitinf/ frond of 

 Jf. J)cclienianH.s. This I consider inadmissible. The parts mistaken 

 by Lesquereux for fruit are, as the specimen clearly shows, nothing 

 (Ose than alternate; elevations and depressions in the marginal jiortions 

 of the ramuli caused by a wavy margin such as is not luicommon 

 among membranaceous algic. 



Haliserites Dechenianus (io]i|)., v;ir. lineatus I'n., nov. var. PI. x^ Fig. 7. 



In No. 8 the frond is regularly dicliotomous throughout; divisions 

 linear, sometimes somewhat narrower at the base, chiefly 2.25""" broad. 

 The divergence of members is from 30° to 44°, chiefly about 40°. 

 Midrib well defined throughout, but small. Margins regular. 



Tiiisapi)ears t<)corres])Oiid to the narrow form of (Joppert's //. Dechoi- 

 imiKs and, according to Mr. Prosser, it was so identified by Lescpie- 

 reux. It would seem better, how^ever, in view of the conspicuous differ- 

 ences bi^tween it and the preceding, to distinguish it by a varietal name, 

 for which I would suggest the oiu', given above. 



Histoiro dos Vrg. FoshiIos, \^. (57, PI. v, Vli, and ix. 



