174 ART. 7. 1. IJIMA : HEXACTINELLIDA, IV. 



to me from the descriptions of Lambe and Schulze as well as 

 froai my own observations, may be summed up as follows : 



rarenchyntalia, oxydiactins under 8 mm. length and 41 /^ 

 breadth. 



The small diactins with 2 or 4 knobs at the middle and 

 of 0.28-1.37 mm. length, mentioned by Lambe as occurring in 

 the dermal and gastral layers and seen also by Schulze, are 

 apparently either those that enter into the composition of hypoder- 

 mal beams together with the paratangentials of oxypentactinic 

 hypodermalia or what might be called the hypogastralia. 



Prodal oxydlaciliis, as long as GUmm. with a thickness of 

 300 /A 



Hypodermal oxxjpcnlact'mn, mostly with orthotroi)al (/.<?., re- 

 gularly cruciate) paratangentials, which are smooth and measure 

 aljout 2.2 mm. in length. In those oxypentactins which stand 

 out as prostalia, the paratangentials and the base of the shaft-ray 

 have a densely granular surface. 



Dermalla, rough pentactins ; with rays rounded at end, 160- 

 180 /-« long and 10-13// thick. Exceptionally the dermalia are 

 diactinic. 



(Jasiralia, similar but somewhat smaller hexactins, with rays 

 of 80-100// in length. 



Oxyhexasters, numerous ; each very short principal with two, 

 straight, moderately strong and slightly rough terminals ; 100-120 

 fi in diameter. Many are hexactinose (then up to 138 y. dia. or 

 axial length) ; some others are hemihexactinose. 



Discodasten, aliundant especially in the deeper parts, 228- 

 320/-« (as a rule 260/-«) in diameter. Principals, short being 5-5 

 of the entire arm-length. Terminals, nearly straight, slightly 

 rough, 3-10 (most usually 4) in number to each slightly expanding 



