12 ME. P. II. CAEPENTER ON THE GENUS ACTINOMETEA. 



weichung allerdings vorluuulcn, cr liegt ganz vaiy Seitc, doch ist dies m cht die Ursac h 

 des Untcrschiedes, cs gibt A'ielmehr aucli Comatulen von der gewohnlichen Anordnung 

 der Furcben, bci denen gleicbAvobl der Mund seitlicb, die Afterrohre central steht. Fig. 

 von C. multlraiUata (PI. I. fig. 4). Die fragliclie Abweiebung beruhrt vielmebr darauf, 

 dass die fiinf Furcben nicbt symmetriscb fiir die fiinf Gruppen der Arnic vertbeilt 

 werden, sondern dass von den I'iiiif Furcben cinzolne berrscbend werdcn und Aeste an 

 die meisten Arme abgebcn. Indcni diesc Hauptiurcben, nacbdem sic die Scbeil)c 

 umzogen, sicb wieder anuiibcrn, so cntstebt der Scbein eines Cirkels. An in Weingeist 

 aufbewabrten Exemplaren siebt man indcss, dass es kein gescblossener Cirkcl ist;" and 

 furtber on (p. 10) be says, " Icb werde daber bei den Arten wo fiinf centripetale Furcben 

 bcobacbtet sind, den Isvimen Alecto in Klammer dem Gattungsnamen Comatula beifiigen, 

 wo aber weniger Furcbenstiinime den escentriscbon Mund erreicben, den Ts'amcn Acti- 

 nometra demselbon Gattungsnamen Comatula i'olgen lassen. Also z. B. Comatula 

 {Alecto) europoia; Comatula [Actinometra) Solaris." 



Miiller does not appear to bave been acquainted witb De Freminville's name of An- 

 tedon ; but be distinctly states tbat Leacb's genus Alecto was constituted a year earlier 

 tban Lamarck's Comatula. He bad in bis earlier communications employed tbe two 

 indifferently and as equivalent to one anotber ; but wben be became acquainted witb tbe 

 type represented by Comatula solans and elevated it into a new genus, or ratber sub- 

 genus, Actinometra, in contradistinction to Alecto, be retained Lamarck's name Coma- 

 tula, probably on account of its being so well known, and employed it to designate the 

 genus in wbicb he included the subgenera Alecto, Actinometra, and Comaster. 



Thus the sole character by which Miiller distinguished the first two of these subgenera 

 from one anotber was tlie number of groove-trunks reaching the peristome, irrespective of 

 tbe position of tbe mouth. It is therefore easy to understand tbat, as many of the spe- 

 cimens which he examined were dry, and as in others, although preserved in spirits, the 

 arms were contracted over tbe disk so as completely to conceal it, he was unable satis- 

 factorily to determine more than three species of Actinometra. Two of these. Act. Solaris 

 and Act. Walilberyhii, have been already mentioned ; the third was tbe small Comatula 

 rotalaria of Lamarck. 



(§9) The Asterias 2)C('liii('l«' of B-ctzius, wliich presented the same " Bildung des 

 Scheitels ' as Act. Solaris, resembled it so greatly in other respects, that Miiller 

 regarded the two as almost identical, or, at any rate, as presenting only varietal 

 differences ^ 



He seems also to have come to the conclusion that the other species described by 

 Rctzius, the Astcrias muUiradiata, Linn., bad a prior claim to this specific name over 

 either of the similarly named types described by Goldfuss (Comaster) or Lamarck (Co- 

 matula muUiradiata); for he described it as " Comatula (Alecto) multiradiata nob."-. 

 It is difficult to understand why he caUed it Alecto; for he had already^ described this 



' 'Gattung Comatula' p. 52. ■ Ihid. p. 25. 



^ "Wiogmann's Archiv, 1843,_i. p. 133, and ' Gattung Comatula,' pp. !i, 10. 



