64 PKOCEEDINGS OF THE NATIONAL MUSEUM vol.81 



dermal hilt rays. Form h is smaller than form «, measuring 68ja to 

 80^ in diameter. The nmnber of terminals in a perianth varies 

 from 9 to 12. The marginal teeth of the terminal plate are 3 or 4 

 in number and seem to occur frequently among the parenchymalia 

 or subgastralia of the basal parts of the entire stock. 



Oxyhexasters occur abundantl}^ both in the subdermal and sub- 

 gastral layers, being more numerous within the former layer, and 

 least numerous in the middle parts of the parenchyme layer. Each 

 principal ray usually bears four or five, sometimes only two, diverg- 

 ing terminals. The principals and terminals of the oxyhexaster of 

 E. oweni are somewhat slenderer than in either E. hnperialis or E. 

 marshalli, but observation of the specimens, which may be referable 

 to E. oweni in this collection, shows that the principals are fre- 

 quently thick or that they occasionally have small knoblike swellings. 

 In general, the principals that are provided with four or five termi- 

 nals seem thicker than those beset with only two or three terminals. 



The lophocome is probably absent. 



The thin and rather short diactins do not exist in the strands of the 

 comitalia which are provided with four tubercles at the center. 



The oscularia consist mainly of the common diactins, with either 

 two oppositely or four cruciately disposed central knobs. Frequentlj^^ 

 they are intermingled with many more pentactins, tetractins, and 

 stauractins. Generally speaking the diactins are commonly located 

 near the edge of the oscular membrane, and the other forms stand 

 outside or in among them in mode of occurrence. The state of the 

 oscularia mentioned above nearly resembles that occurring in E. 

 marshaUi. 



The sieve plate shows parenchymalia consisting mainly of 

 tetractins and diactins. The latter seem to occur more abundantly 

 among the parenchymalia than do the former. Frequently diactins, 

 which are provided with one to four short tubercles at the center, 

 occur among the parenchymalia. 



The small and large gastral pentactins are thinly beset with small 

 prickles near their distal ends. Paratangential rays measure 100/x 

 to 160/x long and C/.t to 8/jl thick near the center. The distal ray meas- 

 ures 44(V to 528ft in length. Besides these pentactins, large tri- 

 radiates and quadriradiates frequently occur. These are also 

 tuberculated at the ends of the rays. The former have a smooth, 

 straight basal ray, ending in a small, distinctly tuberculated pro- 

 tuberance, measuring about 715/x long and 22/a thick at the center. 

 Paired rays are 45/i long, strongly diverging, slightly curved inward, 

 and also tuberculated at the ends. 



The basalia have a very broad, miter-shaped anchorhead, measur- 

 ing 72/x across from tip to tip of opposed teeth. The latter are weakly 



