Bibliographical Notices. 347 



now acquainted with thirty-two, which belong to six genera, and 

 are the representatives of four families. More than half this 

 number, including two new genera, were discovered by the ' Chal- 

 lenger ; ' and twenty-one of the species (i. e. more than 65 per 

 cent, of the known forms) are due to British exploration conducted 

 on H.M.SS. ' Porcupine ' and ' Challenger.' The present Report forms 

 a complete and masterly monograph of the whole group. 



Chapters I.- VI. are devoted to Morphology. Each factor in the 

 structure of a Crinoid is separately described, the modifications 

 presented in the different living forms are reviewed, and their rela- 

 tions to allied fossil forms discussed. The habits and parasites of living 

 Crinoids, as far as known, are likewise fully dealt with. This por- 

 tion of the work is of the greatest importance, for it renders possible 

 a more exact knowledge of extinct forms, and throws light upon 

 numberless points in their structure, and consequently upon the 

 classihcatory position of many doubtful forms as to which palaeon- 

 tologists were hitherto only able to conjecture. To attempt to 

 summarize the chief points of this section is beyond the scope of 

 a general notice, and we must therefore content ourselves with 

 referring those interested in the subject to the Report, assuring 

 them that palaeontologist and anatomist alike will find a mine of 

 information and of careful investigation. 



Dr. Herbert Carpenter follows Dr. Leucliart in separating the 

 stalked Echinoderms from the remainder of the group, under the 

 name Pjelhatozoa ; and he ranks the Crinoidea, Blastoidea, and 

 Cystidea as independent classes of this division, in preference to 

 the course taken by some writers of regarding the two latter groups 

 as subclasses or orders of the Crinoidea. The term Crinoidea is 

 thus limited to the strictly brachiate forms for which it was pro- 

 l)osed by Miller. This step appears to us the right one ; and the 

 reasons adduced by the author are alike cogent and logical. The 

 old divisions of the Crinoidea into Articulata, Tessellata, and Cos- 

 tata, adopted by Job. Muller, have been shown by several writers 

 to be altogether untenable, and with the advance of knowledge to 

 have become practically meaningless. Dr. Herbert Carpenter, in a 

 former volume of this journal (ser. 5, vol. vii. p. 296, 1881), pro- 

 posed the name of Neocrinoidea for the Mesozoic, Tertiary, and 

 Recent types, whilst that of Palseocrinoidea, introduced by Mr. 

 "Wachsmuth, comprised the Palaeozoic types. The chief characters 

 which distinguish these two well-marked divisions were enumerated 

 in the paper referred to, and need not be recapitulated here. The 

 relations of the JMeocrinoidea to the Palueocrinoidea have a chapter 

 devoted to their discussion in the Report ; and light, chiefly of an 

 anatomical character, is thrown on the classihcatory position of a 

 number of doubtful fossil genera by the knowledge acquired from 

 recent forms, which, if insufficient at present in some cases to solve 

 the difficulty, at least paves the way for its solution when more 

 perfect fossil material is available. 



The affinities of recent Neociiuoidea to the Palaeocrinoidea are 

 obviously relative rather than direct. On the other hand, between 



