60 Mr. F. A. Tiather—Suffr^esfed 



tainty of occurrence; instead, tliercforc, it will be necessary 

 to use a brace, or even a simple rule, placed above the 

 symbols of those brachials that are included in the cup. Tims 

 11 V)Y would indicate the secundibrachs, while conveying the 

 additional information that they were fixed. 



In cases where some only of the free brachial series bear 

 pinnules, it would be well to apply the Latin terminology to 

 those brachials without pinnules, whether free or fixed, and 

 the Greek to those with pinnules. Thus, 1-11 Br . Ill Br . 8 St, 

 indicates that both primibrachs and secundibrachs are fixed, 

 that the tertiobrachs are free but do not bear pinnules, that 

 the next series of arm-ossicles are free and bear pinnules, and 

 that there are eight free arms to a ray. The best way of 

 representing the number of ossicles in each series will be 

 discussed presentl}^ 



If the term " Free brachials " be used in the sense here 

 ascribed to it, it can no longer be applied to the distal un- 

 branched ends of the arms. If it is really necessary to have 

 a special term for these ossicles, the word " finials " may be 

 appropriately conveyed from architectural terminology. The 

 word " terminals " already has its special use in Echinoderra 

 niorjjhology. The symbol for finials may be/ when they do 

 not bear pinnules, and F when they do. In all formuh\3 the 

 last or right-hand term of the brachial series should always 

 be understood as applying to the finials, so that there will 

 rarely be any need to use the special symbol f. For the 

 same reason it seems unnecessary to have difierent terms to 

 express pinnulate and non-pinnulate finials, although, strictly 

 speaking, non-pinnulate finials are homologous only with the 

 last pinnule borne by the finials of a pinnulate arm. 



Another difficulty arises with regard to the word " axil- 

 lary." As has been pointed out, each pinnuliferous brachial 

 is morphologically an axillary. Consequently, if the morpho- 

 logical terminology be followed, su|)posing that the ossicle on 

 which a pinnulate arm first branches be the primaxil, then 

 the two ossicles that this supports are the secundaxils; and 

 if there are six distichals the sixth will be the scptimaxil. 

 The septimaxil then, in this case, is the same as the distichul 

 axillary. It will therefore be convenient to distinguish those 

 axillaries on which a pinnulate arm itself branches as " main- 

 axils ; " and instead of alluding to them individually as 

 " monostichal axillary," " distichal axillary," and so on, they 

 may be spoken of as " first nuiinaxil," " second mainaxil," 

 and so on ; or they might j)osslbly be called " monaxil," 

 "distaxil," tetraxil," " octaxil," v^cc. In the symbols, the 

 mainaxils may be distinguished iruui the simjile axillaries by 



