MONOGRAPH OF THE EXISTING CRINOIDS. 



275 



ventral to the central canal (thus giving the portion of the distal border of the cirrals 

 which is ventral to the transverse ridge a slanting direction toward the. tip of the 

 cirrus), while the mass of the segments dorsal to the central canal is pulled proxi- 

 mally for a distance which is as much less than that to which the ventral part 



FIG. 319. 



cnr; 



FIG. 320. 



FIGS. 319-320. 319, LATERAL VIEW OF BEGENEBATING CIRRI FROM A SPECIMEN OF TROPIOMETRA MACRODISCUS FROM 

 SOUTHERN JAPAN. 320, ABNORMAL AND NORMAL CIRRI OF A SPECIMEN OF COMASTER DISTINCTA FROM THE LESSER 

 SUNDA ISLANDS. A, A CIRRUS FLATTENED DORSOVENTRALLY, WITH THE DORSAL PROCESSES DOUBLED AND PLACED 



LATEBALLY, IN (a) DORSAL AND IN (6) LATERAL VIEW. S, A NORMAL CIBBOS, LATERALLY FLATTENED, VIEWED (a) 

 LATERALLY AND (6) DORSALLY. 



of the segments is extended as the difference in volume between the two 

 ligament masses, the extension of the small ventral ligament mass being com- 

 pensated by a comparatively small contraction of the large dorsal ligament mass 

 (figs. 322, p. 277, and 587a, pi. 13). 



