4 ALGITES. 
Genus ALGITES, gen. nov. 
A generic term for those fossils which in all probability belong 
to the class Alge, but which, by reason of the absence of 
reproductive organs, internal structure, or characters of a trust- 
worthy nature in the determination of affinity, cannot be referred 
with any degree of certainty to a particular recent genus or 
family. 
1.—Algites valdensis, gen. et sp. nov. 
Type. Carbonaceous impression from Ecclesbourne, near Hastings 
(Fairlight clay). British Museum. Pl. I. Fig. 1. Registered 
number V. 2857. 
Thallus in the form of dichotomously divided branches radiating 
from a centre ; the branches terminating bluntly. 
The apparently dichotomous habit and the shape of the thallus 
at once suggest a resemblance to a number of algal genera, such 
as Chondrus, Zonaria, Dictyota, Rhodymenia, Nitophyllum, and 
others. Chondrus crispus (L.), Stackh., seems the most likely 
species among recent forms with which to compare the Wealden 
impressions; its more resistant fronds appear better adapted for 
preservation than the more delicate structures of hodymenia or 
Zonaria. So far as habit is concerned there is indeed a striking 
resemblance between Algites valdensis and Nitophyllum Bonnemaisont 
(Lyngb.)' as figured by Harvey ; but an equally strong resemblance 
may be traced on comparing the fossil specimens with examples 
of other recent genera. The extreme variability of Chondrus 
crispus 1s well known, and, as Mr. Murray pointed out to me, the 
broader type of thallus, such as we have in Algites valdensis, is 
indicative of quiet pools or gently flowing water, and in marked 
contrast to the narrow filiform branches of specimens growing in 
swiftly running currents. This difference of habit, and its close 
connection with the mode of life, is worth noting with reference 
to fossil forms, although in the present instance it would hardly 
be admissible to draw any conclusions from the breadth of the 
thallus branches when we are in doubt as to generic relationship. 
1 Harvey, pl. xxiii. fig. 2. 
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