the Morphology of the Echinodenns. 109 



comparison between their Ilycrinus and Bathycrinus Aldrich- 

 ianus as is attributed to them bj Prof. Perrier. 



He further mentions a remarkable specimen with five 

 basals which are not united, and are almost as large as the 

 radials. It cannot be Ilycrinus (D. & K.), which has quite 

 small and very closely united basals ; but if it is not a mon- 

 strosity, I am quite prepared to accept it as a new genus, 

 IlyocrinuSj Perrier, with the specific name recuperatus. I 

 must protest, however, against its appearing on the same page 

 of Perrier's article among the list of Crinoids in the Paris 

 Museum as Hyocrinus recwperatus. This is especially con- 

 fusing, as there is already a well-known genus Hyocrinus^ 

 which was established by Sir Wyville Thomson in 1876. 



According to Prof. Perrier's list, the Paris Museum also 

 contains an undescribed species of Pentacrinus^ viz. P. aste- 

 rius, Miller ; or is it possible that this is the original Penta- 

 crinus which was described by Guettard, and was named 

 Isis asteria by Linnaeus, Pentacrinus caput-medusm by Miller, 

 and has been finally described as Pentacrinus asteriusj 

 Linn., sp.? 



Another instance of the superficial manner in which Prof. 

 Perrier has examined the work which he is supposed to be 

 criticizing is afforded by the first line of the following state- 

 ment*: — "Les Pentacrinus et Metacrinus ne different d'ailleurs 

 que par le nombre des pieces calcaires {pieces radiales) qui 

 se disposent en file pour soutenir les cinq premieres paires de 

 bras, et peut-etre n'y avait il pas necessite absolue de cr<^er 

 pour cela deux noms de genres distincts." The genus Meta- 

 crinus was suggested by Sir Wyville Thomson ; but no other 

 generic name has been established, as hinted by Prof. Perrier, 

 on account of the difference of this type from that of Penta- 

 crinus proper, which dates back to the time of Miller, as Prof. 

 Perrier knows. It is true that in my preliminary report upon 

 the ' Blake ' Crinoids f I mentioned the number of radials as 

 a difference between Metacrinus and Pentacrinus^ because it is 

 the character by which the two types can be distinguished at 

 a glance ; but I likewise stated that the radials of Metacrinus 

 bear pinnules, which is not the case in Pentacrinus. If Prof. 

 Perrier will take the trouble to refer to pp. 339 and 340 of 

 the '■ Challenger ' Report he will find that the two genera 

 also differ in the characters of the stem, cirri, arms, basals, and 

 disc. Nevertheless, with this statement and the figures illus- 

 trating it before him, he tells us that the only diffei'ence 



* ' rievue Scieutifique,' May 30, 1885, p. 691. 

 t ±iull. Mas. Comp. Zool. vol. x. no. 4, p. 1(37, 



Ann. & Mag. N. Hist. Ser. 5. Vol. xvi. 9 



