January 10, 1902.] 



SCIENCE. 



61 



the lee shore, and foi* a considerable dis- 

 tance inland, was very offensive. Tliis was 

 ■due to the Peridinium itself, and not to 

 animals killed by it. In character it was a 

 modification of the ordinary odor of decom- 

 posing organic matter, and was mostly due 

 to the dead organisms cast up on the shore. 



7. A considerable list of other species 

 of chlorophyl-bearing dinoflagellates were 

 present in the water mingled with the 

 Peridinium, and these, particularly several 

 species of Ceratium, largely increased in 

 numbers simultaneously with the increase 

 •of Peridinium, though to a comparatively 

 slight extent. 



8. The only pelagic organism that 

 ■seemed to take advantage of the great 

 abundance of Peridinium, as a food supply, 

 was Noctiluca, which towards the end of 

 the visitation became abundant, and fed 

 upon the Peridinium in large numbers. 



9. But a single species constituted al- 

 most the entire mass, this apparently be- 

 longing to the genus Gonyaulax Diesig. 



10. It was impossible to correlate the 

 enormous multiplication of the organism' 

 with any physical or chemical condition of 

 the water. The cause of such a phenomenon 

 remains for future investigation. 



Coelenterata. — Siphonophores and cteno- 

 phores were taken in far greater abund- 

 ance, as to both species and individuals, in 

 the plankton this year than we have ever 

 before seen in the waters of our western 

 coast. Worthy of mention, also, is the 

 fact that Valella, which at rare intervals 

 appears in enormous abundance on the 

 coast, was found to be throwing off medusa 

 buds in great numbers during May and 

 June. 



Whether the richness in pelagic meta- 

 zoan life, seen not onlj^ in the groups here 

 mentioned, but also in the Pteropoda, 

 Heteropoda, Sagitta, Salpa, Doliolum, etc., 

 may have been correlated with the condi- 

 tions which resulted in the enormous de- 



velopment of Peridinium, it is impossible 

 to say owing to the lack of data from pre- 

 vious observations. 



Perhaps the most interesting observa- 

 tions on the Coelenterata were those made 

 by Mr. Torrey on the longitudinal fission, 

 from the base oralward, of a species of 

 Sagartia. 



Echinoderviata. — Of the several interest- 

 ing questions in connection with the speci- 

 ography and ecology of the echinoderms, 

 which received attention, mention may be 

 made of two. The representatives of this 

 branch of the animal kingdom, the most 

 common and generally distributed over the 

 area in which work was carried on, are an 

 Astropecton {A. erinaceus Gray?) and a 

 Toxopneustes (T. pileolus Ag. ?). Few 

 hauls were made anywhere that did not 

 secure specimens of these species, the 

 Toxopneustes being particularly abund- 

 ant. A single haul of the dredge on Sta- 

 tion XIII. off Point Vincente in thirty- 

 five fathoms brought up about twelve thou- 

 sand specimens, by a careful estimate, and 

 little else! Now the type of Toxopneustes 

 pileolus is a littoral animal occurring 

 everywhere on rocky shores. The forms 

 dredged are of a different style. They are 

 somewhat flatter, the spines are more slen- 

 der; and the color is lighter; yet the two 

 grade into each other. It is almost certain 

 that we have here the differentiation of 

 two species in progress and nearly com- 

 plete, bathymetrie range being the chief 

 differentiating factor. 



A large quantity of material and consid- 

 erable data for the further study of this 

 point were gathered. In a somewhat sim- 

 ilar way Astropecton is a distinctly bifur- 

 cate species. Indeed, one of the forms has 

 sometimes been considered as a Psilaster. 

 Their intergradation is, however, from our 

 summer's observations proved to be com- 

 plete. Longer spines with intermarginal 

 plates, purplish and bluish color and 



