HEXACTINELLIDA. 23 



The calycocomes (V. 2h, h^) are, on an average, about 225jU, in diameter, the 

 primary rays being 9)u, in length; each capital um, 6"75ju, in length and 14"5)u. in 

 breadth, ends in two to four roughened secondary rays tipped with button-like disks. 



Hemidiscohexasters (V. 2k, k^), IOO/a in diameter, occur but rarely ; the primary 

 rays end in one to three secondary rays tipped with disks having four to six long 

 recurved teeth. Fig. 2l shows an exceptional form, 91ju. in diameter, with thick 

 primary and secondary rays, the latter again dividing into two or three short 

 branches. 



The microdiscohexasters (V. 2m) are 43)u. in diameter, with primary rays 5 ■ 5/a in 

 length, and with a convex capitulum, whence about six disk-tipped secondary rays arise. 



Winter Quarters : (1) one specimen (A), the type, and a fragment (B), February 28, 

 1902, McMurdo Bay, 36 m. (20 fms.) ; (2) a small specimen (C), No. 4 hole, January 

 30, 1902, 75 m. (41 fms.) ; (3) a fragment (D), No. 12 hole, September 8, 1903, 

 45-55 m. (25-30 fms.). 



Sub-Family Lanuginellin^. 



Anoxycalyx. 



Lanuginellinse without Oxyhexasters, with Grraphiocomes. 



Anoxycalyx ijimai. 

 (Plate III, fig. 7, and Plate VII., figs. 2-2gi.) 



Sponge in form of a small compressed pyriform sack, with the surface studded 

 with small conules and small flattened pyriform buds. With slender tufts of long fine 

 diactin pleuralia and basalia. The orifice narrow and oval, with a plain rim, and 

 without marginalia. Autodermalia stauractins (mainly) and pentactins, with the odd 

 ray proximal, more rarely tauactins and angular diactins ; hypodermal pentactins 

 confined to the conules ; autogastralia hexactins, with large microdiscohexasters, with 

 graphiocomes, and very large strobilocomes. 



The largest of the three small specimens is 2 • 2 cm. in the length of the body, and 

 7' 5 cm. in total length, i.e., including the pleuralia; the greatest width is 1"7 cm. 

 and the thickness 7 mm. ; the slit-like orifice is 4 mm. in width. The largest buds 

 attain a length of 2 mm. 



The skeleton is mainly formed of bundles of diactins. 



Spicules. The diactin principalia of the bundles are very slender, wavy, 

 tapering to fine points, and roughened at the ends ; a much thicker kind are isolated, or 

 with slender comitalia. PL VII., fig. 2a, shows a parenchymal triactin x 150. The 

 slender wavy pleuralia attain a length of 5 cm. 



The autodermalia are chiefly stauractins (VII. 2b), with each ray 234 x 12jli, 

 slightly spined, curved inwards, rounded at the end ; occasionally these spicules have 

 thick club-like rays (VII. 2b*). 



