12 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 81 



and is echinated prominently, while the paratangential rays are 

 somewhat curved and spined only distally, measuring 100/a to 140/x 

 in length. The distal ray is represented by a vestige in the form of 

 very short, terminally pointed spines. 



Canalaria pinules are in this, as in other members of Pheronema, 

 nearly entirely absent. 



Amphidisks of three kinds — macramphidisks, mesamphidisks, and 

 micramphidisks — are found in the dermalia and in the parenchy- 

 malia. 



The macramphidisks (fig. 1, ;/') are 160/a to 220jU, long and have bell- 

 shaped terminal disks that attain a diameter of 68/* and a height 

 of 63/x. The shaft is 8/x thick and roughened by a few round tuber- 

 cles on the surface. Each disk has eight broad, spade-shaped, 

 terminally slightly pointed marginal rays. 



The mesamphidisks (fig. 1, A, k) are mostly distributed sparsely 

 in the parenchymalia, and are beset with 8 to 12 slender terminally 

 pointed marginal rays on the broad bell-shaped terminal disk, which 

 attains a length of 90/x, to 125/a and is 52/* in diameter. The shaft 

 also has round tubercles on the surface and measures 8/* in breadth at 

 the center. 



The numerous micramphidisks (fig. 1, i) occur everywhere, and 

 are especially abundant in the gastralia. They are 20/t to 40/*, rarely 

 as much as 48/*, long. Their terminal disks are bell-shaped, about 

 lO/i long and 8/* broad, and have 8 to 12 marginal teeth, which 

 sometimes are not easy to observe distinctly. The shaft is rough 

 and is beset with numerous sharply pointed microspines. 



The microuncinates are very abundant in the parenchymalia and 

 vary in length from 140/i to 230/i, becoming extremely attenuated 

 toward the posterior end and covered with short stout spines, the 

 basal part of which is nearly perpendicular to the shaft on the ante- 

 rior part of the same spicule, and the distal part of which is strongly 

 or weakly bent and hooklike in appearance. 



Besides this microuncinate, there occur the other small uncinates, 

 which are entirely similar to the above-mentioned large uncinates in 

 shape and which vary considerably in size. It is therefore evident 

 that the large and small uncinates of these forms are connected 

 by transitional forms and do not seem essentially different from one 

 another. 



In the parenchymalia, the large robust hexactins and pentactins 

 are found. The hexactinic parenchymalia (fig. 1, a) are seemingly of 

 quite variable dimensions. Many rays are about 0.5 mm to 1.7 mm 

 long and 80/i broad near the spicular center. They are usually 

 smooth throughout the entire surface and taper gradually toward 

 the sharj^ly pointed end. 



