Mr. F. A. Bather on British Fossil Crinoids. 313 



Nothing conduces so much to the advancement of science as 

 a uniformity of terminology, especially if such terminology 

 be based on scientific principles. That of the Crinoidea is 

 only just assuming shape and fixity, and that it does so at all 

 is due chiefly to the labours of Dr. P. H. Carpenter. To him 

 I am indebted for some notes explaining the terms which will 

 in future be used by himself and by Messrs. Wachsmuth and 

 Springer: these notes are quoted as P. H. C. (MS.). To 

 these terms I shall adhere so far as my judgment will permit 

 me. I shall also adopt the terms proposed by the same autho- 

 rities in Wachsmuth and Springer's paper " Discovery of the 

 Ventral Structure of Taxocrinus &c." (Proc. Acad. Nat. Sci. 

 Philadelphia, 1888, p. 354, footnote 3), with one exception : 

 these terms are quoted as W. & S. & (J. 



CVo?n« = Crinoid ruinus the stem. — W. & S. & C. 



Ca/y.r = Criuoid skeleton minus stem and free arms. — W. & S. & C. 



Dorsal cup=&\\ parts of the calyx below the origin of the free. arms. — 

 W. & S. & C. I should myself have preferred to retain " calyx " for 

 the dorsal cup, and to have used some such word as "cyst"'' in its 

 place ; " calice " is the natural French word for " cup,'' and the alter- 

 native " la tasse dorsale " smacks a trifle too much of the tea-table. 

 Proposers of technical terms should remember two things: to avoid 

 words already overweighted with meanings ; and to use words that 

 can be easily transferred to other tongues : hence the advantage of 

 Latin or Greek over the vernacular. But in this instance I content 

 myself with a protest. 



Tegmen=tha.t part of the calyx lying above the origin of the free arms. 

 This one term includes both " disk " and " vault *' of W. & S. & C, 

 since I do not believe in the existence of a structure " covering the 

 disk.'* This cannot be argued out here, and will be better discussed 

 when treating of the Camerata. The term " teginen calycis" was 

 used in the same sense by Zittel (' Palpeontologie,' 1879). 



Infrabct sals = the radially situated circlet of plates proximal to the stem ; 

 not always present. This term is preferable to " Under-basals," 

 which Dr. Carpenter always uses, because the latter word is a mon- 

 grel, half Latin half English, and cannot be used in any language as 

 " Infrabasal " can. 



Basals=t\\e interradially situated circlet of plates either proximal to the 

 stem or ventrad of the Infrabasals when those are present. The 

 " parabasals " of some authors. 



Radiate = the radially situated circlet of plates ventrad of the Basals, and 

 this circlet only.— P. H. C. (MS.). 



Brachials, " In forms with 5 undivided arms (e. g. Symbathocrbms) the 

 Radials bear the Brachials directly ; and throughout the whole group 

 every joint beyond the Radial is morphologically a Brachial, as is 

 shown both by comparative anatomy and bv embryology.'' — P. H. C. 

 (MS.). 



Costals= Brachials of the first order ; the second and subsequent primary 

 radials of W. & S. are now called 1st, 2ud, &c. costals, up to the 

 axillary. " Miller used this term in Apiocrinus, Pentacrinus, and 

 ComatulaJ'—P. H. C. (MS.). 



Distichate = Brachials of the second order; used bv Miller. — P. H. C, 

 (MS.). 



Ann. & Mag. N. Hist. Ser. 6. Vol. v. 23 



