12 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



Diameter of radial pentagon at base, 1.5 mm.; median height of articular 

 face, measured along the inclination, 0.3 mm.; maximum width, 0.7 mrn.; dis- 

 tance from center of rosette to middle of dorsal outer edge of radial, 0.6 mm.; 

 distance from center of ventral face of radial pentagon to middle of ventral edge 

 of radial, 0.5 mm. ; to apex of interradial angle, 1 mm. 



COMACTINIIN.E. 



The interarticular ligament fossa? are nearly or quite as high as broad. 



The distal border of the interarticular ligament fossae is usually slightly 

 lower interiorly than exteriorly. 



There is a more or less abrupt change in direction between the outer edge 

 of the interarticular ligament fossae and that of the muscular fossa?, the latter 

 projecting more or less outward. 



The inner ends of the muscular fossa? are more or less within the inner distal 

 angles of the interarticular ligament fossae. 



The muscular fossae in general slope more or less upward from the median 

 axis of the joint face to the periphery. 



In addition to these characters the centrodorsal has no cirri, or (except in 

 Comatulides) possesses a single crowded and regular row; in some cases the 

 radial cirri are suppressed, leaving one or two in each interradial angle. 



COMATULA ROTALARIA. 

 See figs. 958, 959, pi. 1. 



COMATULA SOLARIS. 

 See figs. 960-962, pi. 1. 



COMATULA PECTIN ATA. 

 Figs. 17, IS, p. 15. 



The articular faces of the radials lie in a plane parallel to the dorsoventral 

 axis of the animal and including the proximal edge of the radials. The sculpture 

 is moderate in relief. 



The dorsal ligament fossa is wide laterally and narrow dorsoventrally, nearly 

 oblong. It is nearly or quite five times as broad as high. The proximal border 

 is not at all, or only slightly, convex, curving sharply upward at either end. 

 The ligament pit is large and reniform, much larger than the transversely oval 

 central canal. 



The transverse ridges of adjacent articular faces are in lateral contact, and 

 the ends of the dorsal ligament fossae may be more or less confluent. Inter- 

 radially the interarticular ligament fossae are separated by a narrow parallel 

 sided furrow, which is closed distally by the apposition of the muscular fossae. 



The interarticular ligament fossae are about as high as broad. Their lateral 

 edges slope inward at the base, but are nearly or quite vertical for most of their 



