OP ARTS AND SCIENCES. 355 



Lessonia. — Species of this genus certainly exist on the Pacific 

 coast, but of their specific cliaracters we are still as ignorant as in the 

 time of Harvey. Specimens which find their way to the east are too 

 imperfect for determination. Some of the supposed specimens of Les- ■ 

 sonia are nothing but the bladderless leaves of Macrocystis. Others 

 are the young fronds of Pliyllospora. I have specimens from Oregon, 

 collected by Mr. E. Hall, which may belong to L. fuscescens, but they 

 are too imperfect to warrant giving a decided opinion. 



*25. Pterygophoha Californica, Ruprecht. " Pflanzen aus 

 dem nordl. Theile des Stell- Oceans," p. 17, Plate V. Santa Cruz, 

 Cal., and northward. — May not this prove to be a Lessonia? Fruit? 



*2G. PosTELSiA PALMiEFORMis, Ruprecht, 1. c. p. 19, Plate VI. 

 Santa Cruz, Cal., northward. — Fruit'? 



27. Alaria esculenta, Grev. (inc. A. Pylaii, Grev.) Cape Cod 

 northward ; north-west coast. 



28. Alaria fistulosa. Post, and Rupr. North-west coast. 



29. Alaria margixata, Post, and Rupr. North-west coast. 



30. CoSTARiA TuRNicRi, Grev. (inc. C. Mertensii, Ag.) North- 

 west coast. 



31. DiCTYONEURON Californicuii, Ruprecht, I.e. p. 24, Plate 

 VII. — I have never seen specimens of this plant, but from Ruprecht's 

 figure one might infer that it is a species of Costaria. North-west 

 coast. 



32. Laminaria fascia, Ag. New York northward. — This be- 

 longs to the genus Pfiyllitis, of Le Jolis's " Liste des Algues marines 

 de Cherbourg." 



33. Laminaria dermatodea, De la Pyl. Peak's Island, Portland 

 harbor, Me., common just below low-water mark, W. G. F. ; East- 

 port, Me., Prof. D. G. Eaton. — Recognized by the very short root 

 fibres and flat stipe, gradually expanding into a thick coriaceous frond 

 of lanceolate outline ; often, when exposed, splitting to the base of 

 the stipe. Time and mode of fruiting ? 



34. Lamixaria saccarhina, Lmx. New York northward. — 

 Southern limit? West coast? 



35. Laminaria longicruris, De la Pyl. Common from Boston 

 northward. Old Lyme, Conn., Prof D. C. Eaton. — Not always 

 readily distinguished from the last. The hollow stipe is not always 

 diiiguostic, since it is only when the plant has attained a certain age 

 that the stipe is hollow. On the other hand, old stipes of L. sacca- 

 rhina are sometimes hollow for a short distance. The stipe of this 

 plant is infested by a species of Sphceria. The Laminaria trilaminata, 



