ECHINODEKMS. 75 



large, stout, blunt spines, with rugose tips, arranged irregularly in 

 one or two rows, or scattered unevenly, while there is usually a 

 group of from three to six smaller spines on the spaces be- 

 tween the ribs at the bases of the arms, and often one or two on the 

 interbrachial spaces, near the edge of the disk. Similar small, blunt 

 spines, or tubercles, extend along the dorsal surface of the arms, either 

 in single or double rows. The grains covering the disk and upper and 

 lateral surfaces of the arms are quite uneven in size and prominence, 

 with more or less numerous small, flattened plates or scales scattered 

 among them, and in many parts these scales are more regular, with the 

 grains arranged around their borders, this condition being most appar- 

 ent on the arms ; the prominent tubercles and spines are developed 

 from the center of similar scales or plates. The under side of the disk 

 is more regularly granulous. The arms are rather slender and well 

 rounded dorsally, dividing first at about their own diameter from the 

 ends of the radial ribs ; the distance from the first to the second division 

 of the arms is about equal to the larger radius of the disk ; and from 

 the second to the third usually somewhat greater. The terminal divis- 

 ions are numerous and very slender. The arm-spines, toward the base 

 of the arms, are small, stout, fusiform, terminated by two acute spi- 

 nules, and form transverse rows, usually from five to seven, but farther 

 out they became shorter and stouter in rows of two to four ; still farther 

 out the two or three terminal spinules become curved, and near the ends 

 of the arms they have the form of minute hooks. 



Color of one dried specimen uniform brownish yellow ; of the other 

 light grayish brown, with many narrow transverse bands of darker 

 brown across the arms and radial ribs, changing into irregular streaks 

 and spots of the same color on the interradial spaces. 



The larger specimen measures, from center to end of radial ribs, 16"^™ ; 

 center to edge of interbrachial spaces, 13™™ ; center to first division of 

 arms, 21™™; diameter of arms near base, 5™™ to 6™™; beyond first divis- 

 ion, 4™™; beyond second division, about 3™™j diameter of larger spines 

 on radial ribs, 2™™; height, 2™™. 



Pearson's Point, D'entricasteaux Channel, Tasmania, seven fathoms, 

 clinging to Primnoella australasice y Capt. Ralph Chandler, (Poughkeep- 

 sie Soc. Nat. Science.) 



