MONOGRAPH OF THE EXISTING CRINOIDS. 107 



Although in reality continuous with its extensions along the ventral 

 surface of the arms, for convenience the visceral mass is assumed not to extend 

 out farther than the second brachial, this being the point at which it com- 

 monly ruptures on being detached from the animal. 



Visceral skeleton. A skeleton, in the form of scattered spicules, developed within 

 the visceral mass. 



W. 



Wachsmufh and Springer's Law. See Law of Wachsmuth and Singer. 

 Wall-sided. The ossicles of the division series and arm bases are said to be wall- 

 sided when they are closely appressed against each other, and their appressed 

 sides are sharply flattened (see figs. 43, p. 77, 88, p. 145, 94, p. 155, 96, p. 159, 

 99, p. 160, 100, p. 162, 101, 102, p. 163, and 558, pi. 5). 

 Water pores. (1) The madreporic pores. 



(2) the intersegmental pores. 

 Whorl. Of cirri; a row. 



EXPLANATION OF SYMBOLS. 



In the description of a comatulid the number of the cirri is expressed by Roman 

 numerals, and the number of their component segments by Arabic ; thus "cirri XVII, 

 25" means that the animal has 17 cirri, each with 25 segments. 



The division series are designated by the letters "Br" preceded by the figure 

 (in Roman numerals) denoting the numerical sequence of the series; thus "IBr" 

 refers to the primibrachs (figs. 1, p. 60, 3, p. 62, 29, p. 71), or the first division series 

 following the radials (R R),the "costals" of P. H. Carpenter's terminology in his later 

 works, or the "second and third radials" of the Challenger reports; IIBr, orsecundi- 

 brachs (fig. 29, p. 71), is equivalent to Carpenter's "distichal series," IIIBr to 

 "palmar series" (fig. 29, p. 71), IVBr to "post-palmar series," etc. The individual 

 elements of the division series are indicated by so-called inferior numbers; thus 

 118^ means the "first distichal" or the first ossicle following the first division series 

 and IIIBr 2 means the second ossicle of the "palmar" or third division sencs. The 

 ossicles of the free undivided arm are referred to simply as brachials. 



It should be emphasized that the employment of these symbols is merely a matter 

 of convenience and does not in any way imply an homology between division series 

 bearing the same designation in different genera. 



The presence of a syzygy is indicated by the use of the symbol " +"; thus 

 "IIBr 4(3 + 4)" means that the second division series (the secundibrachs or "dis- 

 tichals") are composed of four ossicles, of which the third and fourth are united 

 by syzygy (fig. 29, p. 71). 



The outer pinnules of an arm arc numbered in regular sequence, P u P 2 , P 3 , P 4 , 

 etc.; the inner pinnules are lettered, P a , P 6 , P c , P d , etc. (fig. 6, p. 63). The 

 IBr or "costal" pinnule (only found in the genus Eudiocrinus) is given as P c (figs. 

 83, p. 136, 84, p. 137), the IIBr or "distichal" pinnule as P D (fig. 81, p. 134, on the 

 outer side of the second ossicles above the first axillary), and the 1 1 1 Br <>r " palmar" 

 pinnule as P P (fig. 81, p. 134, the two apparently small pinnules on the second 



