Bulletin, Vanderbilt Marine Museum, Vol. VII Plate 70. 



Pentacta arae Boone, type: spicules from tissue from the median ven- 

 tral surface near the intermediate ambulacrum: a, hexagonal thin scale from 

 outer layer of bodywall ; calcareous deposite from inner layer of bodj^vall : 

 b, circular and oval disks, variously perforate; c, crosses with four- and six- 

 arms ; d, crescents and crescentlike bodies with double curve ; e, clavate perfo- 

 rate and non-perforate rods; f, i, rodlike bodies with four transversely banded 

 lobes; 1, convolute needlelike spicule with curved ends. 



Spicules from tissue from the median dorsal surface of body : needlelike 

 spicules; m, bow-shaped spicules, with subdistal bend of both apical portions; 

 n, straight spicule with one end bifurcate and elongate spicules tri- or quadri- 

 sinuate, with both apices bent or curved; o, six- and seven-rayed anchor 

 spicules ; g, spiral spicules of three kinds ; f , clavate irregular bodies ; h, disks ; 

 j, clavate and oval perforate disks; k, C-shaped and convolute spinose spicules. 



Figures a, b, c, d, and e, magnified, X 43; f, h, i, j, k, 1, m, n, o, magni- 

 fied, X 65. 



