438 



MERISTIC VARIATION. 



[PART I. 



III.). DI: LOIMOL, P., M,',,i. ^oc.paleont. suisse, 1877 1879, p. 24.".. 

 PI. xix. ti.js. :}!)/,, 40 r/, 41 a. 



I I II 



l-'i.i. !.".!. I. Niitinal four-rayed basal of Tetracrinus moniliformis (from Birmens- 

 II. A tin.' rayed basal of the same species from the same locality as I. 

 III. A tive-ray<d basal of the same species from Oberbuchsitten. 



(After P. DE LORIOL.) 



*6G7. Cupressocrinus gracilis. This form has normally a 5-rayrd 

 calyx, and a ">-sidrd basal plate containing only 4 canals round 

 the central canal ( Fig. 132, I). Varieties have been seen in which 



667 a. 



1 1 



Fir;. 132. Cupresmcrinn* iinn-ilix. The normal form of the basal is shewn in 

 I. A fnrin with live canals round the central is represented in II, and in the 

 specimen shewn in III there are three peripheral canals. See No. 667 </. 



(After L. SCHDLTZE.) 



there are 5 (Fig. 132, II), or 3 (Fig. 132, III.) such peripheral 

 canals. The stalk is normally 4-sided, but in the varieties it is 

 citlu r .')- <>r .Vsid.-d in correspondence with the number of canals. 

 C. elongatus : stalk may be either 4- or 5-sided. The 

 species ('. iiitliit/is has normally 3 canals in the (circular) stalk. 

 Sciu'LTZE, L., Deiikxrlu: A/,: Wiss., Mut/i.-itdt. Cl., 1.S67, xxvi. 

 pp. 1 30 and 136, PI. I. tig. 2 b, and PI. III. figs. 2 c and 2 i. [Cp. 

 No. 6G7.] 



668. Abnormalities in the manner and frequency of branching in the arms of Crinoids 



leading tn (.Teat nunit rii'al \aiiatimi have been often recorded. See CARPEVI i R, 

 C/i.///. /{,!>., X\M. 1't. ix. ]>. 28; id. I'hil. Trans., 1866, Pt. 2, p. 725 PL, also a case 

 tit' tir,li i anus in Antedon rosacea, the ul'imnnalit y nut liein^ symmetrical, DF.MIY, 



l'i-"i-. l;. I'luja. Sur. i-'.iiin., ix. p. l*n. I'l. ; also case of A. rosacea having abnormal 



branches in t\v.> arms symmetrically placed with regard to the axis. BATKSON, W., 

 /'. /. g., is'.in. p. r.sl. !i^. I (in, w in Coll. Sur-;. Bias.). The abnormal arms were 

 //, and <, of the usual nomenclature, as shewn in Fig. 133. For details see original 

 description. 



Encrinus liliiformis : anmngst other abnormalities case 

 given in which <>m- nf tin- radii bore only one arm. v. STROM- 

 I;KI K, ]',/!, i, ,nt., iv. j). 169, PI. xxxi. fig. 3. 



