ART. 12 HEXACTINELLID SPONGES — OKADA 49 



in axial length. The short principals are 12fj. long and generally 

 bear three widely divergent terminals, which are 24/a in length, 

 nearly straight or slightly bent, and thickest at the base, thinning 

 out to a very fine caliber toward the end. They are quite smooth on 

 the surface. In the same spicule all the claws are similar in shape 

 and of nearly equal size. 



Transitional forms connect them with the normal onychaster, and 

 they all occur in the parenchyme. Sometimes all the principals are 

 supplied with two, occasionally three, terminals, and at other times 

 they are either hemihexactinic or quite hexactinic forms, showing an 

 increase in diameter (6;V to 95)u, in diameter) over normal forms. 

 The tip of the terminal branches is without a trace of a disklike 

 expansion but bears a whorl of two or three short and exceedingly 

 fine prongs, directed obliquely backward. 



Scopulae are of one kind, forming delicate spicules 300/x to 350yDt 

 long in the entire length. They are arranged perpendicularly to the 

 surface, forming a bundle around the proximal ray of dermal pen- 

 tactins, their terminal branches protruding forward from the sponge 

 wall. The shaft is generally simple, straight, 280;ii to 300/i long, and 

 gradually attenuated toward the conically pointed end. All the 

 surfaces are quite smooth. The number and shape of the terminal 

 branches are subject to considerable variation. They are slender, 

 4 to 8 in number, 30/a to 45/a long, nearly the same breadth throughout, 

 and quite smooth on the surface. They arise from a prominent 

 thickening at the distal end of the shaft, which is provided with 

 three or four weak protuberances on the surface, 8/a in breadth. They 

 run nearly parallel or slightly divergent on the whole. The most 

 characteristic feature of the spicule is the distal thickening of the 

 shaft, which has several protuberances on the surface. 



A most peculiar feature of the species is the total absence of 

 uncinates. I have searched particularly for them in all the prepara- 

 tions, but I must confess that I am still in doubt regarding them. 



EURETE FARREOPSIS Carter 



Eiiretc farreopsis Carter, Ann. jNIag. Nat. Ilist., ser. 4, vol. 19, p. 122, pi. 9, 

 figs. 1-7, 1877.— F. E. ScHTJLZE. Challenger Rep., vol. 21, p. 295, pi. 79, flgs. 

 5-8, 1887. 



A single small, almost completely preserved, specimen and several 

 fragments of E. farreopsis were collected from two stations. (Table 

 14.) The species resembles Pararetc carterl in essential spiculations, 

 excei^t for the curved terminal branches of scopulae and for the 

 mucl\ more delicate discohexaster. The specimens in question deviate 

 from the type specimens as follows, but these variations are deemed 

 too slight to warrant the establishment of a new species: 



118040—32 4 



