43G M ERISTIC VARIATION. [PART I. 



it must !. a r;ire occurrence. In Tetracrinus the four-rayed condition 

 is normal, and it is an especially interesting circumstance that in this 

 fin-Hi Variation to Imt h a I'm- rayed and to a three-rayed condition has 

 In i 11 observed. Fur nearly all the references to the following facts I 

 am indebted t<> tin- useful collection of evidence on the subject given by 

 BATHER, F. A., Quart. Jour. <;>ol. 6'oc., 1889, p. 149. 



Fntir-rai/ed varieties of five-rayed forms 1 . 

 (544. Holopus rangi. This genus was originally described from a 



1 -rayed -pecimeii by ]>'< )|;i:K;NY, Mag. de ZuoL, 1837, Cl. X., PI. III. 



Subsequently, ~> rayed examples were obtained and this condition was 



found to be normal (see, ( ' AKPIATER, Chall. Rep., xi., Pt. xxxn., p. 197). 

 '!4.'i. Eugeniacrinus : departure from 5-rayed condition very rare. 



Among many hundreds of calyces in Brit. Mus. one only is 4 rayed, 



BATIIKK, /. <., p. 1 55. 

 G4G. E. nutans : I rayed specimen at Tiibingen figured in QUENSTEDT'S 



Atlas to /W/v/;,,v, /. l),'nfschl. Taf. cv., h'gs. 179 181. Another case 



I.OI.MI ss, /'. // /,/,/,/ Germanics, i., p. 163, PL i., fig. 4, now in Poppels- 



dorf .Mus., Hour. ( Itather). 

 !47. E. caryophyllatus : 4-rayed specimen seen at Stuttgart. Such 



a specimen |Mhe same] Uosixus, Tentaminis de Lithozois . . . Prodr. Arc., 



tab. in. (Jlamb. 1719). Another case GOLDFUSS, I.e., fig. 4: now in 



Poppelsdorf Mus. (Bather). 

 G4S. Pentacrinus : a 4-rayed stem-joint from the Chalk, MANTELL, G. 



A., (,'enl. o/Swsex, 1S22, p. 183 : now in Brit. Mus., E. 5501 (Bather). 

 <;4!. Pentacrinus jurensis : 4-rayed specimen. The stalk had only 



4 sides, one being quite flat. This fiat side had an articulation for a 



cirrus. DE LoRiOL, P., Paleont. Franc. Terr, jur., Ser. 1, Paris, 1886, 



p. 112, PI. r\i.iv.,/i>. 6. 

 G50. P. subsulcatus : 6 joints of a 4-rayed stem, ibid., p. 117, PL 



651. P- dumortieri: 8 joints of a 4-rayed stem, ibid., 1887, p. 186, 



PL n.xil., tigs. G and 6 a. 

 G52. P- dubius : 4-sided stem quite regular. Basle Mus., BATHER, I.e., 



p. Ids. 



6 :>.S. Balanocrinus subteres : 4-sided stem quite regular, ibid. 

 G54. & bronni : "the articular surface shows 4 sectors quite regularly 



disposed ; this peculiar character is continued over the whole series of 



joints, 'Jli in number." ////>/. 

 G55. Encrinus fossilis : a 4-rayed calyx, &c., v. STROMBECK, A., 



Z (./!,: <l. <t- at. (jfol. Gi'x., I., 1849, p. 158 et seqq. See also Palceonto- 



gra/Ji ;<!, 1855, iv., p. 1G9, PL xxxi. figs. 1 and 2. 

 65G. E - fossilis: two -1-rayrd calyci's with mutilated arms, v. KOEXEN, 



AUi. k. (,'*. ,/. M'/.s.v.. (Jiittingen, 1887, xxxiv. Pkys. KL, p. 23. 

 657. Antedon rosacea : 4-rayed specimen, CARPENTER, P. H., Chll. 



/''/'., xxvi. Pt. i,.\. p. '27. Four-rayed Japanese specimen, ibid. 



Anot her in I !ril . .M us. //</./. 



1 4-Bidrd sti'in joints uiiiirtrrniiiinl. I'rscn, /',,/,'//x 1'nU'nntt.. 1837, p. 8, PI. n. 

 fig. 8, a, b, <-, </. Siv iilso AIM-IN, Ann. >in,l M,i ;l . \ . //., 1843, xi. p. 203. 



