26 
SIPHONACEiE. 
III. UDOTEA. Lamour. 
Root fibrous, much branched. Frond erect, stipitate, expanded, flabelliform, more 
or less incrusted with calcareous matter, concentrically zoned, composed internally of a 
plexus of longitudinal, subparallel, unicellular, branching filaments. Sporangia “lateral, 
globose.” ( Kutz .). 
The genus Udotea is intermediate between Halimeda and Codiurn ., differing from 
the former in habit and from the latter in having the filiform cells of which fit is com- 
posed incrusted with carbonate of lime. The amount of incrustation varies much in 
different species. In U. fiabellata , which very closely agrees in structure with Hali- 
meda , the calcareous matter forms a solid, smooth, and somewhat polished crust, 
completely concealing the filaments of which the frond is constructed ; in U. conglu- 
tinata the lime forms a thin coat round each individual filament, but does not conceal 
the filamentous structure of the frond ; and in U. Desfontanesii there is scarcely any 
calcareous deposit, and except in habit the plant is almost a Codium , in which genus 
it was placed by Agardh. Ten species of Udotea are known, all of them natives of 
the warmer parts of the sea. Our U. fiabellata is found in the Indian Ocean, and I 
have received U. conglutinata from Port Natal, S. Africa. 
1. Udotea fiabellata , Lamour. ; stipes simple, short, terete or sub-compressed, 
expanding into a broadly flabelliform, simple or lobed, wavy, concentrically zoned, 
smooth frond ; the margin either quite entire, undulato-repand, crenate, or deeply 
lobulate, sometimes proliferous ; surface thickly incrusted ; concentric zones evident, 
closely set or sub-distant. JDne. Cor. p. 93. Lamour. Pol. Flex. p. 311. Kutz. Sp. 
Alg. p. 502. Corallina fiabellata , Ell. and Sol. Cor. p. 124. tab. 24 {excellent!). 
Hab. Key West, W. H. H. Abundant between Key West and Cape Florida, Prof. 
Tuomey. (v. v.) 
Root a fusiform mass of intricately interwoven fibres, one to two inches long. Stipes 
half an inch to an inch long, terete, a quarter-inch or more in diameter, simple, erect, 
terminating in the broadly cuneate or reniform base of the frond. Frond sometimes 
six inches across, but our specimens are mostly smaller, usually broader than its length, 
more or less cuneate at base, the lateral margins prolonged downwards in old fronds, 
which, therefore, are somewhat reniform ; flabellate, either quite entire with a flat 
margin, or more frequently undulate, lobed at the margin or deeply divided (as Ellis’s 
figure represents) into numerous latinise, which take the form of the primary frond, and 
imbricate each other at the edges. The surface is thickly coated with a calcareous 
crust, and quite smooth ; it is marked at short, but very uncertain intervals, with 
concentric lines or furrows, much more obvious in some specimens than in others, but 
always to be found. The substance is as thick as calfskin and leathery to the touch. 
