322 Reviews — WacJismuth ^ Springer's Monograph on Crinoids. 



" perisomatic system." W. B. Carpenter rightly attached " but little 

 importance to the form of the reticulation as a differential character " ; 

 he was " disposed to regard the perforation or non-perforation by the 

 radiating extensions of the Crinoidal axis [axial nerve-cords] as 

 quite sufficient in itself to differentiate the entire skeleton into two 

 series of plates." ^ To some extent this division corresponds with 

 Wachsrauth and Springer's division into primary and secondary ; but 

 since they include the ambulacrals among primary plates (p. 38), it 

 is clear that their * perisomic ' is not a synonym of their ' secondary.' 

 Here, then, is a term used in a different sense by each writer in 

 succession, apparently incapable of strict definition, and corresponding 

 to no morphological idea. Why can we not bury it for good and all? 

 This mighty monograph affords a fitting mausoleum. 



In designating the different radii and interradii of the calyx, the 

 anal interradius is of course 'posterior,' while the radius opposite 

 is ' anterior ' ; in the natural position of the crinoid, the right and left 

 sides correspond with the right and left of one observing the cup 

 from its anal side. The radii adjoining the posterior interradius are 

 naturally designated 'right and left posterior,' while the interradii 

 adjoining the anterior radius are the ' right and left anterior.' I have 

 called the radii next the anterior radius the ' right and left anterior ' ; 

 and the interradii next the posterior interradius, the ' right and left 

 posterior.' Messrs. Wachsmuth and Springer would substitute the 

 appellations 'right and left antero-lateral' and 'right and left postero- 

 lateral ' ^ respectively. My mode of expression may be a tiny trifle 

 less precise, but it is open to no misconstruction, since in a five-rayed 

 symmetry only one radius can possibly be meant by ' right anterior ' ; 

 moreover, it is three syllables shorter. 



So far, it will have been seen, I have no quarrel with the 

 terminology adopted by Messrs. Wachsmuth and Springer ; I differ 

 from them merely in the interpretation of a few of the terms, a 

 matter in which their opinion (where it is a definitely stated opinion 

 and not a loose mode of expression or a slip) is of at least as much 

 value as mine. We come now to a case in which, after 

 much epistolary discussion with my departed friends Carpenter and 

 Wachsmuth, I decided to adopt a different and entirely new set 

 of terms. This was in connection with the successive series of 

 brachials. It seemed to me, as also to Carpenter, that the expressions 

 " brachials of the first, second, or third, etc., order," and even 

 "primary, secondary, or tertiary, etc., brachials," were too long and 

 cumbrous. In their stead Carpenter proposed " costals, distichals, 

 palmars, post-palmars, second post-palmars, third post-palmars, 

 etc." These were accepted by Wachsmuth and Springer, and 

 originally by me also. But I soon discovered that such an 

 expression as " the third second post-palmar " was not merely 

 cumbrous and inelegant, but also one involving (for me at least) 

 a more serious effort of memory or of calculation than circumstances 



^ " Researches on the Structure .... oi Antedon rosaceus^^ : Phil. Trans., 

 1866, p. 742. 

 ^ They have " autero-lateral " (p. 37), but it must be a misprint. 



