August 23, 1912] 



SCIENCE 



243 



maiming all the mea in the room and filling the 

 vessel with a cloud of scalding steam (p. 111). 



These quotations will suffice to show the 

 characteristics of the book. It can hardly be 

 considered as other than somewhat sensational 

 and often perhaps exaggerated, but to the 

 student of chemistry it will ailord much food 

 for thought and reflection, and this, we think, 

 is its chief value. The title of '' Modem 

 Chemistry" is well chosen, for the book is 

 brought thoroughly down to date. 



The illustrations are unequal. Some of the 

 half-tones are excellent, while some of the 

 wood-cuts are execrable, wholly unworthy of 

 the book, and others have evidently been 

 handed down from early times. Quite unique 

 are the three cuts representing the reaction 

 between phosphorus pentachlorid and sulfuric 

 acid, which have a decidedly astronomical ap- 

 pearance, cometic, one might say. 



The book is printed on thick, light paper 

 and the typography is good. The only error 

 we have noticed is the name of F. W. Clark 

 instead of Clarke, and this is several times 



J. L. H. 



Cienophores of the Atlantic Coast of North 



America. By Albert Goldsborough Mayer. 



Publications of the Carnegie Institution, 



162. 1910. Pp. 58; pi. 17. 



Dr. Mayer is well qualified to give an ac- 

 count of our ctenophore-fauna by many years 

 observation at numerous localities between 

 Newfoundland and the West Indies, all but 

 three of the 21 species here recorded having 

 come under his own observation. And his book 

 is made doubly welcome by the fact that 

 American ctenophores have received little at- 

 tention in recent years. 



The first few pages are devoted to a brief 

 statement of geographic distribution, three 

 groups of species being recognized on our 

 coast : " cold-water forms," " intermediate " 

 and " tropical." The first are described as 

 common north of Cape Cod, and occasional as 

 far south as Hatteras, the second extending 

 from Cape Cod to northern Florida, while the 

 records of the tropical species are chiefly from 



the Tortugas, though some of them " drift 

 northward in summer to the region of Vine- 

 yard Sound." The recognition of these three 

 groups is justified; but exception must be 

 taken to the limits assigned the first, for two 

 of its members, Pleurohrachia pileus and 

 Beroe cucumis are by no means exclusively 

 cold-water species, as is shown by the presence 

 of the former at Bermuda, in the Mediter- 

 ranean and at the Seychelles, and of the latter 

 near Madagascar and in the Malay archi- 

 pelago. Mayer suggests that the Mediter- 

 ranean " Pleurobrachias " might be young 

 LobatsB, but specimens from Naples prove to 

 be typical P. pileus. If we remove these two 

 species from the Arctic group, the extreme 

 southern limit of the latter in winter appears 

 to be New Jersey. The tropical group in- 

 cludes the noteworthy species Hormiphora 

 plumosa, Eurhamphea vexilligera and Folia 

 parallelum, not previously recorded from this 

 side of the Atlantic. An interesting fact 

 pointed out by Dr. Mayer is that we are far 

 less rich in ctenophore species than the Medi- 

 terranean; though certain ones swarm on our 

 northern coasts. 



The general organization of the ctenophores 

 has so often been discussed that Dr. Mayer 

 limits himself to a brief summary of the fea- 

 tures of the gastrovascular system of the six 

 orders, and then proceeds to the descriptions 

 of the species, which occupy the greater part 

 of the volume. These are generally satisfac- 

 tory, the lists of references full, and the figures 

 numerous and unusually beautiful, and there 

 are numerous notes on habitat and on physiol- 

 ogy. No families are recognized, the only 

 divisions being orders, genera and species. 

 The following generic names are abandoned, 

 because preoccupied, Bolina, Eucharis, Ocyrce 

 and Vexillum; as substitutes Dr. Mayer pro- 

 poses Bolinopsis, Leucothea (Mertens), Ocy- 

 ropsis and Folia. Four species are described 

 as new, Pleurohrachia trunnea, Tinerfe lactea, 

 T. heehleri and Leucothea ochracea. But the 

 first is so close to the Hormiphora spatulata 

 described by Chun from the Plankton expedi- 

 tion that I believe the two are identical. 

 Leucothea ochracea is interesting because, to 



