270 THE VOYAGE OF H.M.S. CHALLENGER. 



on the Comatulse before the characters of Actinometra again came under discussion. 

 Messrs. Dujardin and Hupe followed the general lines of Midler's classification, but 

 made some important alterations in it. Leach's name Alecto was abandoned altogether 

 in favour of the later name Comatula, Lamarck ; and Actinometra was restored to the 

 generic rank which Midler had first proposed for it. But the French authors 1 found 

 some difficulty in defining it properly, remarking that " ce genre ne differe guere des 

 vraies Comatules que par la position de l'anus au centre et de la bouche au bord du 

 disque. II en resulte que les gouttieres ambulacraires, au lieu de se rendre a la bouche 

 en suivant la direction des bras comme chez les Comatules, s'inflechissent et suivent le 

 contour du disque." Dujardin and Hupe stated, however, that the mouth of Comatula 

 was only " ordinairement au centre," 2 so that its excentric position could not be regarded 

 as especially distinctive of Actinometra, though this has since proved to be the case. 

 The restoration of the latter type to a distinct generic position was nevertheless a 

 considerable step in advance ; but the mode in which the French authors disposed of 

 some of Miiller's species was very singular. 



The type species of the genus, Actinometra im<perialis of Midler, was subsequently 

 discovered by him to be identical with Comatula Solaris, Lamarck, or Alecto Solaris 

 as he called it at first. But in his concluding memoir 3 it appeared as Comatula 

 (Actinometra) Solaris, and Miiller further expressed the opinion that Asterias pectinata, 

 Betzius, which he had also found to be an Actinometra, is merely a varietal form of the 

 same type. Dujardin and Hupe, however, regarded these three forms at Vienna, Baris, 

 and Lund as respectively representing three different species. They referred the 

 Lamarckian type at Baris to Comatula, but the other two forms to Actinometra; 

 although Miiller had expressly pointed out both in the Monatsbericht 4 (1846) and in the 

 Abhandlungen 5 (1849) that Lamarck's originals were specifically identical with the type 

 of his Actinometra. 



Dujardin and Hupe gave no reason for their restoration of a specific name which 

 Miiller had withdrawn in favour of that established at an earlier date by Lamarck ; and 

 one can only conclude, therefore, that they had overlooked Miiller's final references to 

 the type, confining themselves to quoting those of 1841 and 1843, which were made 

 before his visit to Baris. 



On the other hand the French authors left Asterias multiradiata, Betzius, in the 

 genus Actinometra, to which it had been originally assigned by Miiller, though he 

 subsequently withdrew it. But it would almost seem as if this were due to their not 

 having consulted Miiller's later writings, to which they made no reference. For no place 

 was assigned in their classification to the individuals in the collections of Beron and of 



*&• 



1 Op. cit., p. 208. • Ibid., p. 194. 



3 Abhandl. d. k. Akad. d. Wiss. Berlin, 1847 [1849], p. 248. 4 Loc. cit., p. 178. 



5 Loc. cit, p. 248. 



