142 
ECTOC ARP ACEiE. — Ectocarpus. 
iv. 
or rarely alternate ; propagula (spores?) elliptical, dark coloured, sessile. Haw. 
Phyc. Brit . t. 200. J. Ag. Sp. Alg. 1 , p. 21. 
Hab. On Algae, etc. between tide-marks, in rock pools. Boston, Dr. Silas 
Durkee. (v. v.) 
Filaments capillary, not very densely tufted, from four to eight inches long 
much branched, with a principal stem and lateral decompound branches. All the 
divisions mostly opposite and spreading. Propagula ellipsoidal, dark-coloured, 
plentifully scattered on the ramuli. 
9. Ectocarpus Durkeei ; tufts not very dense ; filaments robust, decompound, 
much branched, the branches and the lesser divisions alternate ; the angles acute 
and ramuli erecto-patent, attenuated, alternate or secund ; articulations of the 
branches shorter than their breadth ; propagula elliptic-oblong, obtuse, subsessile, 
constricted at the base, transversely striate. (Tab. XII. E.) 
Portsmouth, New Hampshire, Dr. Durkee (No. 35). (v. s. in Herb. T. C. D.) 
Tufts two inches long, hair- like, spreading. Filaments much branched, with an 
evident leading stem, and decompound, alternately divided branches ; the main stem 
and larger branches much more robust than the branches of second or third order, 
and remarkable for the shortness of their articulations, whose dissepiments are 
somewhat constricted. The angles are all acute, and the branches and ramuli con- 
sequently erect. The propagula are borne toward the base of the smaller branches, 
and several are generally found together on the same branch. Colour olive-green. 
The ramification of this plant is most like that of E. Pitt oral is, but the fruit is 
nearer in form to that of E. granulosus. It seems a distinct species, so far as I can 
judge from the examination of a single specimen. 
Plate XII. F. Fig. 1, Portion of a filament of Ectocarpus Durkeei , magnified 
jig. 2, minute portions with propagula ; jig. 3, a propagulum ; the latter figures 
highly magnified. 
10. Ectocarpus Mitclielloe ; tufts feathery ; filaments very slender, decompounclly 
much branched, the branches and their lesser divisions alternate ; the ultimate 
ramuli approximated ; angles wide, and branches and ramuli patent ; ramuli 
attenuate, articulations of the branches twice or thrice as long as broad, of the 
ramuli once and half as long, propagula elliptic-oblong or linear, quite sessile and 
very obtuse, transversely striate, several together. (Tab. XII. G.) 
Nantucket, Mass., Miss A. Mitchell, (v. s. in Herb. T. C. D.) 
