22 
SIPHONACEiE. 
Ashmead. Conch Key and Key Biscayne, Prof. Tuomey. — Var. @ cast ashore at 
Key West. W. H. H. (v. v.) 
Surculi prostrate, robust, sometimes nearly as thick as a goose’s-quill, sometimes as 
a crow-quill, glabrous, glossy, shrinking much in drying and becoming longitudinally 
furrowed, vaguely branched, rooting at intervals of one or two inches ; the root long, 
branched, and fibrilliferous. Fronds rising from the upper surface of the surculi ? 
scattered, on long, glabrous, naked stipites, flabelliform in outline, pedate or digitate, 
the branches spreading, simple or forked, fastigiate, densely set throughout with 
imbricated, four or five-ranked ramenta. Pamenta one to four lines long, varying 
much in length and somewhat in ramulification on different specimens. Normally they 
are patent or recurved and sub-bipinnate, or pinnate with pectiniform pinnules ; that 
is, the ramentum is oppositely pinnate, the pinnas closely set, straight, subulate, or 
filiform, mucronulate, and furnished along one (the lower) side with unilateral ramuli 
of similar form. In different specimens the number and development of the processes 
of the pinnee vary ; sometimes they are 5 or 6, and of considerable length ; some- 
times but 2 or 3, and these very short. In var. /3 they are absent altogether, and 
the ramenta of much greater length than is usual in var. a ; but I have seen speci- 
mens so completely intermediate that I dare not make two species of these seemingly 
different forms, particularly as both occur in the same locality. The normal form 
has been admirably figured by Bory in the plate above quoted. I fear that C. phlce- 
oides of that author can only be regarded as a variety of the present species. 
II. HALIMEDA. Lamour. 
Root fibrous, much branched. Frond erect, dendroid, branching, articulato-con- 
stricted, with flattened internodes (or articulations ), coated with a smooth calcareous 
crust, and composed internally of a plexus of longitudinal, sub-parallel, unicellular, 
branching filaments. (These filaments, which constitute the medullary stratum of the 
compound frond, are constricted at intervals, and at each constriction emit a pair of 
opposite, horizontal, di-trichotomous, corymbose ramelli, whose apices cohere together 
into a false epidermis or periphery.) 
The species comprised in this genus were placed by Ellis and Linnasus in the genus 
Corallina , where they remained till 1812, when Lamouroux very properly separated 
them to form the present group. The resemblance to Corallina is merely external. 
Both genera have jointed fronds, encrusted with calcareous matter, but here the resem- 
blance ceases. The structure, colour, substance and fructification, which determine 
affinities, are widely different in Corallina from what they are in Hcdimeda. In this 
