AND ITS RELATIONS TO RECENT COMATUL-S. 199 



(pi. xx. fig. 4 a), Ant. Gillerioni (pi. xx. fig. 7b), and Ophio- 

 crinus Hyselyi (pi. xxi. figs. 10 a, 10 6); but he does not seem 

 to have been aware of its meaning ; for he neither mentions it, 

 nor does he ever mention any ligainent-fossae except the large 

 dorsal one below the articular ridge. 



VIII. — "We now come to a type of Comatulcs with which Gold- 

 fuss was unacquainted, although it is represented by the Cretaceous 

 species Hertha mystica, described by Hagenow * in 1840, and 

 by most recent Comatulcs. It was described by d'Orbigny t as 

 follows under the name of Decameros : — " Nous reservons ce nom 

 aux Comatules dont le calice se compose d'une piece centrale 

 epaisse, et sur laquelle s'appliquent immediatement cinq pieces 

 brachiales, sans pieces basales." In addition to the recent An- 

 tedon and Alecto, two fossil species were referred by d'Orbigny 

 to this type, and Hertha was subsequently added by Pictet. But 

 as their nomenclature was incorrect, the classification which they 

 proposed, although a sound one and based on good morphological 

 principles, was never really adopted. Quenstedt, indeed, makes 

 no mention of it except that he regarded forms without external 

 bases as monstrosities of Ant. costata. Thus, after describing 

 this species on p. 58 of his ' Jura,' he continues — " Es scheinen 

 auch Missbildungen vorzukommen ; der fig. 11 (tab. 88) fehlen 

 z. B. die Zwischenradiale, und die Badialglieder zeigen aussen eine 

 breitere glatte Flache, aber die porose Saule bleibt noch." It is 

 strange that he had not only overlooked the ^descriptions of 

 d'Orbigny and Pictet respecting the deficiency of basals in certain 

 Comatulce, but that he was not then aware that this was the con- 

 dition of nearly all the recent Comatulce then known (Comaster, 

 G-oldf., being of course excepted). It seems, however, to be com- 

 paratively rare among the fossil species, most of which have the 

 basals more or less developed externally, though they are occa- 

 sionally wanting at one or two angles of the calyx J. There 

 are two specimens in the . British Museiim which are devoid of 

 external basals, and must therefore be ranked with the Decameros 



* " Monographic der Riigen'schen Kreide-Versteinerungen. ii. Abtheil. Ra- 

 diarien und Annulaten," Neues Jahrb. f Mineralog. 1840, p. 664. 



t Op. cit. ii. p. 138. 



\ E. g. Ant. wquimarginata, A. lenticular is, A. canaliculata (PI. IX. figs. 6 a, 6 b). 

 No external basals have been described in A, italica, while they do not appear 

 in de Loriol's figures of A. Picteti, A. infracretacea, and others, though he says 

 they are " a peine apparentes au dehors." 



