MONOGRAPH OF THE EXISTING CBINOIDS. 



85 



Extraneous arm division. — Arm division resulting from the occasional branching 

 during growth of a linear series of brachials without the loss of the larval arm 

 and without the reduplication of the first two brachials, as contrasted mth 

 Interpolated arm division, or arm division resulting from tho interpolation of 

 division series, each of which is tho exact morphological equivalent of tho first 

 two (or four) brachials of the larval arm, between tho first (or third) brachial 

 of tho larval arm and tho base of a now arm which is tho exact dupUcato of tho 

 original larval arm. 



Fig. 60. 



FIQS 59^-59 THE TERMCAL COMB ON THE PRO.XM.VL P.Nmn.ES OF A SPECIMEN OP COMASTER MULT.BRACHUTA FROM TM 



AUSTRALIA VIEWED LATERALLY FROM THE OUTSIDE (.), VENTRALLV (6), AND LATERALLY .ROM THE INSIDE (c). 



F. 



Finial pinmiles.-The. paire.l piimules termmating the post(-rior ungrooved arms 

 of certain of the Comastericlffi (see fig. 47, p. 81, and pp. 110\ 



First hracUal (Br,) .-Strictly applied, this term refei-s to tho first ossicle beyond 

 the last straight muscular articulation. In most forms the fu-st brachial is 

 the first segment succeeding the last axillary; in E^iocnnns it is the thu-d 

 postradial segment, and in Uintacrinns the thinl post-costal segment. 



