REPORT ON THE CRINOIDEA. 403 



led me to adopt Schliiter's view, as de Loriol * had jireviously done. For I not unfre- 

 •juently met with calyces in which basals might appear externally at some of the angles, 

 but not at others ; while in other fossU types no basals were visible at all. In both cases, 

 however, the basals were present as more or less prismatic rods extending outwards from 

 the centre of the under surface of the radial pentagon somewhat as in the Peiitacrinus 

 decorus represented in PI. XXXIV. fig. 8. But they were not always long enough to 

 reach the edge of the radial pentagon and appear externally between it and the centro- 

 dorsal ; so that one side of a calyx would be that of an Antedon and the other that of a 

 Solanocrinus. Under these circumstances it would seem that Schliiter was undoubtedly 

 right in uniting Solanocrinus with Antedon. But in a Manual of Palaeontology recently 

 published by Hoernes,^ Zittel's classification is still adopted, and Solanocrimis is placed 

 as a subgenus of Antedon, differing from it in the presence of basals on the exterior of 

 the calyx ; while it is also described as represented by a living species and not by fossil 

 ones only. This apparently refers to the doubtful genus Comaster, Agassiz, which is 

 only known from the descrijition given of it by Goldfuss.' AVhatever be the nature of 

 Comaster, however, the supposed difference between Solanocrinus and Antedon cannot 

 any longer be regarded as of generic value. 



NOTE C. 



(Page 68.) 



On the Excenteic Position of the Mouth in Actinometra. 



The genus Actinometra comprises quite two-fifths, if not more, of all the species of 

 li\'ing Crinoids. The character by which it is most readily distinguished at first sight is 

 the excentric position of the mouth, as was pointed out in 1877 * and again in 1879 ;^ 

 while its generic position is recognised by Glaus in the last edition of his Grundzuge der 

 Zoologie with the character "Mund excentrisch" (PL LV. figs. 1,2; PI. LVI. figs. 7, 8; 

 PL LXI. fig. 2 ; see also fig. 3 on p. 92). 



In spite of these facts, however, Hoernes stated in his Palseontology (p. 131) that in 

 recent Crinoids the mouth, is always (stets) in the centre of the disk, which is very far from 

 being the case, as explained above. This error was avoided by Zittel, whom Hoernes 

 usually follows very closely ; though the generic position of Actinometra was not fuUy 

 recognised by the former author, who placed it along with Solanocrinus and Promacho- 

 crinus as a subgenus of Antedon. But all subsequent writers, Hoernes excepted, have 

 recognised that Antedon and Actinometra are totally distinct generic t}^es. 



1 Swiss Crinoids, p. 254. • 2 Elemente der Palseontologie, p. 149. 



3 Petrefacta GermaniiP, vol. i. p. 202 ; see also Journ. Linn. Soc. Loud. (Zool.), vol. xiii. p. 454, 1877. 



* Journ. Linn. Soc. Lond. (Zool.), vol. xiii. p. 441, 1877. 



* The Genus Actinometra, T/Tois. Linn. Soc. Loud. (Zool.), ser. 2, vol. ii. p. 18. 



