Recent Progress in Biology. xix 



mention a few of those which have perhaps more generally or 

 more strikingly attracted attention, some from the enormous 

 labour involved in their preparation, some from the novelty 

 of the material described, and others from the interest of 

 the general conclusions which have been worked out by the 

 authors. Amongst them we may mention Professor Haeckel's 

 magnificently illustrated monograph of the " Radiolaria ; " 

 Mr. H. B. Brady's "Foraminifera," with its revelations of the 

 pleomorphism of the group; Dr. P. H. Carpenter's "Crinoids,' 

 of which beautiful forms he enumerates as many as 180 

 species, and reports that Australasia and Malaysia are amongst 

 the strongholds of an order which was not so very long ago 

 supposed to be on the verge of extinction ; Dr. Gunther's 

 " Deep Sea Fishes ; " the three parts of Professor Herdman's 

 "Tunicata; " the elaborate work on the "Echinoids" and 

 " Ophiuroids " respectively ; of the American naturalists, 

 Agassiz and Lyman ; the Sponge monographs of Sollas, 

 Schulze, Polejaeff, Ridley, and Dendy ; Professor Busk's 

 " Polyzoa," and Professor Allman's " Hydroida ; " Professor 

 Moseley's beautiful work on " Millepora " and " Heliopora," 

 and Mr. Botting Hemsley's comprehensive studies on the 

 "Floras of Oceanic Islands." 



In many cases the writer gives a complete summary of 

 what is known from all sources on the order of animals, of 

 which the memoir treats. Thus, the Pteropods are completely 

 reviewed by Professor Pelseneer, who concludes that these 

 delicate pelagic molluscs may be ranged in a very few 

 (genera, and that the entire order should be merojed in the 

 Gastropods. Professor Allman discusses in full the classifi- 

 cation of the Hydroida, Dr. Lyman that of the Brittle Stars, 

 and so on. Such memoirs give the series of Reports much 

 of the nature of an Encyclopaedia Zoologica. 



A bare enumeration of the authors, and the titles of their 

 treatises, may recall the monotony of Homer's list of his 

 lieroes. I can only excuse myself by retorting that, in my 

 opinion, the workers of the Challenger are heroes, and that 

 the great Zoological Reports constitute no mean epic. 



