CARA.DOCIAN CYSTIDEA FROM GIRVAN. 435 



at least two side-branches, and leading to brachioles which are relatively thin and not 

 longer than the height of the theca. 



§288. Genotype. — Cheirocrinus penniger 'EAcksv . This species was introduced as 

 Cyathocrinitis penniger by Eichwald in 1842 (p. 78, pi. i. f. 10). The holotype was 

 said to come from Wesenberg, and fragments were recorded from Eeval and with less 

 certainty from Pawlowsk. When founding the genus (1856) Eichwald only mentioned 

 Eeval; but in " Lethaea Eossica " (1859, p. 646) he gave the horizon as Calcaire a 

 Orthoceratites, and the localities as Wesenberg and Pulkowa. 



Fr. Schmidt (1874, p. 20) confirmed the localities Wesenberg and Eeval, and fixed 

 the horizon as the uppermost part of the Orthoceras Limestone or Vaginatenkalk. The 

 specimens from other localities or horizons have been referred either by Schmidt (1874) 

 or by Jakkel (1899) to other species. When, therefore, Jaekel (1899, p. 220) gives 

 the locality as " bei Petersburg," this must be understood in a very broad sense. 



The precise horizon of C. penniger is still not clear to me. Lamansky (1905) threw 

 no light on the matter. According to Schmidt (1874) it should be at the very top of 

 the Orthoceras Limestone (B3) and just below the Brandschiefer of Kuckers (Cl). 

 But, though the Eeval specimens may have been found at this horizon, the holotype 

 from Wesenberg must have come either from one of the higher series D, E, or F, and 

 presumably from the AVesenberg Limestone (E) itself, or else it must have been in a 

 drift block of B3, as were some of Schmidt's specimens. 



§ 289. History of the Genus. — As shown by the list of synonyms, this genus was 

 long confused with Glyptocystites, established by E. Billings in April 1854, with the 

 unique genotype G. multipora [sic]. The distinction between the two was recognised 

 by Haeckel (1896), who, however, committed the systematic error of transferring the 

 genotype itself to Callocystis and retaining the name Glyptocystis for the other species. 

 This was rectified by Jaekel (1899) and myself (1900). 



§ 290. The genotype of liomocystites Barrande is H. alter. Dr Jaekel, who has 

 examined the original material, is unable to distinguish this from Cheirocrinus ; and, 

 in the absence of further evidence, I am prepared to accept his decision. H. tertius 

 Barr. is more obscure. Dr Jaekel believes that it will eventually prove to belong to 

 a new genus, for which he proposes the name Leptocystis (1899, p. 222). It appears 

 to diifer from Cheirocrinus in the distribution of the pectinirhombs and in the structure 

 of the proximal region of the stem. 



§ 291. Description of the Genus. — Cheirocrinus has been so fully described by 

 Fr, Schmidt (1874) and by Jaekel (1899), not to mention my more concise interpre- 

 tation (1900), that I propose here to dwell only on the more difficult points and on the 

 statements that need modification. 



The Theca is higher than wide, but the irregular shape of some species, especially 

 our new C. constrictiis, forbids the general application of the term " oval." 



§ 292. The base is often invaginate, but does not seem to be so in some species, 

 e.g. C. alter Barr. sp., C. Walcotti Jaekel, and C. Forbesi Bill. sp. This, therefore, is 



