PROCEEDINGS OF THE \ l'/7o\ I/, MUSEUM. VOL. 38. 



in length. The fourth and following segments arc moderately con- 

 stricted centrally, so that the ends are prominent; this character 

 slowly diminishes in the distal half of the cirri. The cirri are nearly 

 round in basal section, but gradually become slightly compressed 

 laterally and are moderately compressed in the distal portion; this 

 lateral compression is very gradual, and is not attended with an in- 

 crease in the lateral diameter of the cirrus as in Antedon bifida. In a 

 lateral view the dorsal profile of the segments is seen to be slightly 

 more concave than the ventral, especially dist ally, making the proxi- 

 mal and distal dorsal ends of the segments somewhat prominent. 



Disk resembling that of Antedon mediterranea, usually naked, but 

 sometimes with a more or less abundance of calcareous spicules in 

 •he inner part of the interpalmar areas; sacculi abundant along the 

 ambulacra, but small and irregularly arranged in one, two, or three 

 rows, becoming more definitely arranged in a single row along the 

 brachial ambulacra. 



Kadials even with, or extending very slightly beyond, the edge of 

 the centrodorsal, rising in the [nterradial angles of the calyx into a 

 low triangle; I Br, oblong or slightly trapezoidal, two and a half to 

 three times as broad as long, the lateral edges slightly produced and 

 swollen; a shallow groove usually borders this swollen vd^o interiorly, 

 which may be reduced to a small round pit just proximal to the 

 median horizontal diameter of the ossicle. I Br 2 (axillary) roughly 

 a right-angled triangle, the apex rather sharp; lateral edges, which 

 are about half the length of those of the I Br t , somewhat swollen 

 and produced. 



Tin slender arms loo mm. to 110 mm. long; first brachial wedge- 

 shaped, twice as long exteriorly as interiorly, about half again as broad 

 as the exterior length, interiorly jusl in contact basally; the exterior 

 margin is swollen and slightly produced; second brachial irregularly 

 quadrate, larger than the first, though of about the same length 

 exteriorly; synarthrial tubercles sometimes slightly prominent, but 

 usually not marked; third and fourth brachials (sy/.ygial pair) 

 slightly longer interiorly than exteriorly, about half again as broad as 

 long in the median line; fifth brachial slightly wedge-shaped, about 

 twice a- broad as long in the median line, the following becoming 

 more obliquely wedge-shaped, and after t he second ^y/.yi:\ triangular, 

 about as long as broad, soon becoming somewhat less oblique and 

 wedge-shaped again and very slowly increasing in length, being very 

 long terminally. Syzygies occur between the third and fourth brach- 

 ials, again between the ninth and tenth and fourteenth and fifteenth, 

 and distally at intervals of three oblique muscular articulations. 



I', I' nun. to 13 mm. long with seventeen or eighteen segments, 

 the first about as long as broad, the remainder about twice as long 

 as broad, becoming somewhal longer distally; the pinnule is much 



