14 MR. P. U. CAEPENTER ON THE GENUS ACTINOMETRA. 



Avithdrcw it in favour of Comatula ', the " Knopf," or centrodorsal piece of wliicli was 

 described by him as an " Ueberrest der vcrkiimmerten Saule," -uhilc, like his prede- 

 cessors, he mentioned the absence of basals. The existence, however, of external basals, 

 both in Solaiiocrinus and in Comaster, led him to regard them, like Miiller, as generically 

 identical; and he used the name Co??2rf6ifcr for this type in preference to *S'o/««oe;v»?fs, 

 as it " bezicht sich nicht nur auf eiucn lebend und voUstiindig bekanntcn Typus, sondern 

 driickt audi die Verwandtschaft richtig, wie Solanocrinus unrichtig, aus." About the 

 same time D'Orbigny ^, and, a few years later Pictet^, transferred the name Comatula to 

 this last-mentioned type, in which the basals appear externally ; while they revived 

 Linck's name Decacnenms (or, as they named it, Decameros) for the Antedoii of De Fre- 

 minville and the Alecto of Leach. They characterized the genus as only differing from 

 Comatula, in their sense, in the total absence of the five basals, so that the radials 

 rest directly upon the centrodorsal piece. Eortunately, however, this peculiar inversion 

 of the nomenclature employed by Miiller was not destined to last ; for in Bronn's 

 ' Klassen und Ordnungen des Thierreichs'^ all the above genera are united into one, 

 Comatula, which with Glenotremites and another doubtful fossil constitute the family 

 Comatulida?. Saccocoma and 3fars7(pites are restored to the places originally assigned to 

 them by MiUler, in special groups, Costata and Tcssellata respectively, among the 

 unstalked Crinoids ; while Euyeniaerlmis, whicli Goldfuss regarded as nearly related to 

 Solanocrimis, is placed with a few similar forms in a family Eugeniacrinidse, which, toge- 

 ther with the Pentacrinida) and Apiocrinida;, make up the group Articulata of Midler, 



(§ 11) The family Comatulidse was considerably enlarged a few years later by Du- 

 jardin and nupc'\ who included in it, as D'Orbigny and Pictet liad already done, not only 

 the tribes Comatulicns and Saccocomiens, but also the Eugcniacrinicns, which both the 

 above authors had ranked among the stalked Crinoids, while Marsupites, which they 

 referred to the Comatulid;e on account of its calyx being free, was transferred to the 

 Cyathocrinidae by Dujardin, who could " ne voir qu'un caractere secoudaii'c dans 

 Tabsence d'unc tige chez plusieurs de ces Crinoides." He distinguishes the three tribes 

 as follows : — " Nos trois tribus seront suflisammcnt caractcrisc'cs : la premiere, celle des 

 Eugcniacrinicns, par son calice adherent ou pcdoueidc, jamais Libre ; Ics deux autres, 

 dont le calice est libre a I'etat adulte, se distinguent jiarce que celle des ComatuUens 

 porte cirrhes ou rayons dorsaux, dont la derniere, celle des Saccosomiens, est cens^e 

 dcipourvue." 



The position of Exgeniacrimis does not concern us at present. Let us now investigate 

 the species included Ijy Dujardin in the tribe Comatulicns. Under this head he ranks 

 three genera, viz. Comatula, Lam., Actiuometra, Midi., and Comasler, Ag., using the 

 latter name in the sense in which it was employed by Midler and lla-mer, namely as 

 equivalent to Solanoci'hms. Dujardin's genus Comatula, however, is not precisely 

 equivalent to that of MiiUer, who included in it the two genera or subgenera Alecto and 



' LcthoGa geognostica, iii"' Auflage, 1851, Tlicil iv. p. 133, and Thcil v. p. 177. 



- Cours clement, de Palcontol. ot de Gi'ol. stratigraph. 1S50-1852, vol. '2, i. pp. 138, 139. 



=• Traite de Paleontol, (Paris, 1S57) vol. iv. p. 288. " Band ii. Aktinozoen (ISGO), p. 233. 



» Hist. Nat. des Zoophytes, £cliinodcrmes, (Paris, 1SG2) p. 186. 



