Mr. F. A. Bather on British Fossil Crinoids. 321 



with x . They admitted indeed that the small right posterior 

 radial only equalled the upper half of the radial (R) of Den- 

 drocrinus, but the lower half (R + ) appeared to them to be 

 absent, " though perhaps represented in a portion of the large 

 undivided anal plate." This view again may or may not 

 have been correct, but it was hardly consistent with their 

 explanation of the other forms. Nothing was said about the 

 homologies of the anal plates in Hoplocrinus and Baerocrinus, 

 with which genera Wachsmuth and Springer were then 

 unacquainted. 



In 1882, Dr. P. H. Carpenter published an important 

 paper " On the relation of Hybocrinus, Baerocrinus, and Ilybo- 

 cyslites." [Quart. Journ. Geol. Soc. no. 151, vol. xxxviii. 

 pp. 298-312, pi. xi. London, Aug. 1882.] Under the name 

 Hi/bocrinus, Carpenter then included the American genus 

 Hi/bocrinus of Billings and the European Hoplocrinus of 

 Grewingk ; I here follow Wachsmuth and Springer in main- 

 taining the distinctness of the two genera. In this paper while 

 " concurring in the views of Messrs. Wachsmuth and Springer 

 respecting the mutual relations of Hybocrinus, Homocrinus, 

 and Dendrocrinus" Dr. Carpenter is " not altogether in 

 accordance with them as to the relations of these three types 

 to Iocrinus." He "cannot follow their comparison of" the 

 dorsal cup of Iocrinus lt with Dendrocrinus.' 1 This indeed is 

 obvious, for he misquotes their comparison, and states that 

 Wachsmuth and Springer homologize the lower half of the 

 compound radial in Dendrocrinus (PI. XIV. fig. 15, R + ) with 

 the upper axillary plate in Iocrinus (PL XIV. tig. 5, C). The 

 learned Americans are not, it is true, always easy to under- 

 stand, but it is hardly fair to suppose that they talk nonsense. 

 This incomprehensible fiction, however, appears to be the 

 reason why Dr. Carpenter " cannot follow these authors in 

 regarding Iocrinus as the starting-point from which the de- 

 velopment of the anal plates may be traced from one genus 

 of the Cyathocrinida3 [ = Fistulata] to another." "Viewed 

 in a purely ernbryological aspect, Gyathocrinus or a Dendro- 

 crinoid form with the two halves of the 'compound radial ' 

 [R andR + ] united, is a lower type than Iocrinus. For the 

 continuous line of the radials is broken into by the anal plate 

 [x], which is in direct contact with a basal, as in the early 

 Pentacrinoid." This argument assumes, rightly or wrongly, 

 that the anal plate x is homologous with the anal of the 

 An Wow-larva. Further, Dr. Carpenter sees the inconsistency 

 of Wachsmuth and Springer's attitude towards Hybocrinus, 

 and prefers to homologize the whole of the large " anal " 

 plate in that genus with the lower part of the compound 



