Marine Sponges from Japan. 403 



keratose element, which is thus scanty; hence they are 

 softer, not near so tough, and of a light grey colour, which 

 causes them to resemble the open vase-like form called by 

 Dr. Bowerbank "Isodictya infundibuliformis " (Mon. Brit. 

 Spong. vol. iii. pi. liv.) ; but not being the same, it might, 

 for distinction's sake, be termed "Tuba poculum" 



3. Echinonemata. 



One branched specimen, compressed throughout, with the 

 ends flat and expanded, and the spicule of one form only, viz. 

 stout, acuate, arranged in tufts on the surface over a dense 

 interior. Colour brown. Species undescribed. 



4. Holorhaphidota. 



A portion only of a Pachastrella, 2\ in. in its longest dia- 

 meter, but which, being new, is sufficiently interesting for the 

 following brief record of its spiculation, which consists of a 

 very large acerate body-spicule, whose natural length amounts 

 to l-6tli in. (PI. XIV. fig. 14, a and g), a large quadri- 

 radiate zone-spicnle (fig. 14, b) and a crust of minute micro- 

 spined acerates, mixed with a few still more minute sceptrella? 

 and spinispirulaj, one form passing into the other (fig. 14, c, d. 

 and e, f). The body-spicule radiates in bundles from a 

 common centre ; and the quadriradiate, whose shortest arm is 

 directed inwards, has the other three rays spread over the 

 surface among the small microspined acerates &c. Thus the 

 spiculation very much resembles that of Pachastrella amygda- 

 loides (' Annals,' 1876, vol. xviii. pi. xiv. fig. 22, &c), only 

 that the radiate spicule in the present instance has four instead 

 of three arms ; while the absence of the minute stelliform spi- 

 cule, although the spiculation otherwise resembles that of a 

 Stelletta, that is the large acerates are confined to the body 

 and the quadriradiates to the surface &c, induces me to pro- 

 pose for it the name of "Pachastrella stellettodes.' 1 '' For 

 measurements of the spicules I must refer the reader to the 

 illustrations in which fig. 14, a-d are drawn to the scale of 

 l-48th to 1-1 800th inch, e and f being enlarged views of c 

 and d respectively, and g the natural length of the body- 

 spicule. 



