530 CEEAMIACEAE. 



attenuate at the apex and often also at the base. The tetrasporangia are 

 tetrahedrally divided and are borne near the bases of the whorled short 

 branches. The Bermuda plants are larger, coarser, and more gelatinous than 

 the European type and the ultimate cells of the ramelli are more obtuse, but 

 the occurrence of apparently intermediate forms in the West Indies makes it 

 doubtful if they may be satisfactorily distinguished from the European 

 species. (Phyc. Bor.-Am. 2048.) 



Spyridia filamentosa (Wulf.) Harv. is a common plant growing attached 

 to rocks in shallow water in warm bays and tide-pools, or found floating and 

 unattached, often in loose tangled mats. It is commonly 3-6 inches high, 

 with main branching subdichotomous or irregularly lateral, the principal axes 

 ^-4 line in diameter. As in the other species of the genus the branches are 

 clothed, sometimes sparingly, with very delicate hair-like ramelli about i a 

 line long, which under a hand-lens are seen to be transversely zoned, hyaline 

 zones alternating with narrower colored ones. Under a compound microscope, 

 the main branches are found to be corticated, the corticating cells in regular 

 transverse zones in the younger parts; bands of narrower longer corticating 

 cells regularly alternating with bands of broader shorter cells. This species 

 is distinguished from the following by its looser more straggling habit and, 

 microscopically, by the fact that the capillary ramelli are merely acute or 

 apiculate, without recurved hooks. (Phyc. Bor.-Am. 1897.) 



Spyridia complanata J. Ag. grows on exposed rocks between the tide- 

 lines or near low-water mark, as at Hungry Bay, Eed Bay, and Spanish Rock. 

 It is more densely branched, more plumose in habit, and usually a smaller 

 plant than the preceding, growing 2-4 inches high, with tufted compact 

 feathery fronds mostly i-A inch broad. The main axes are slightly flattened 

 and the branches are predominantly distichous. Many of the ramelli, besides 

 having an apiculus, are provided with one or more minute retrorse one-celled 

 subapical barbs or hooks. (Phyc. Bor.-Am. 1947.) 



Spyridia aculeata (Ag.) Kiitz. is similar to S. complanata, but the 

 branches issue in all directions, showing little tendency to be distichous. How- 

 ever, this character seems variable and it is doubtful if these two species can 

 be satisfactorily distinguished, at least so far as concerns the Bermuda plants. 

 The ends of the main branches are often enlarged and hooked, circinate, or 

 tendYil-like, as in the genus Hypnea, constituting the var. Tiypneoides J. Ag. 

 (Phyc. Bor.-Am. 1946.) 



Ceramium nitens (Ag.) J. Ag. is an attractive deep red, brownish red, 

 or yellowish red, copiously branched, thread-like plant that occurs in Hamil- 

 ton Harbor, in the Inlet to Harrington Sound, etc. It forms soft rather 

 lubricous tufts, mostly 3-5 inches high. The main branching is subdichot- 

 omous, wdth one or several somewhat zigzag leading axes. The smaller 

 branches are lateral, subdivaricate or patent, and occasionally seeund, and the 

 apices are straight. Under a microscope the plant is seen to be corticated 

 throughout and more or less nodose, with the transverse septa of the large- 

 celled monosiphonous axis visible through the cortex. The Bermuda specimens 

 seen are sterile. (Phyc. Bor.-Am. 1949.) 



