404 ECHINAXIA AND RHABDOSIGMA, 



apical (as well as the basal) extremity rounded off, and nearly 

 always stouter and much shorter than the normally developed 

 spicules; the extreme forms of these are short straight strongyla, 

 ranging up to 25/x in stoutness, and occasionally down to less 

 than 100/x in length. 



The sigmafa are of two kinds, differing in size and also some- 

 what in shape. The larger (Text fig. 2, d) invariably have their 

 (very finely pointed) extremities recurved abruptly, in a sharply 

 hook-like manner, and are frequently only so slightly contort as 

 to appear more or less Q-shaped when viewed from the side; 

 more usually, however, their degree of torsion is such that the 

 planes in which their opposite extremities are curved, are in- 

 clined at an angle of not less than 90°. The smaller sigmata 

 (Text-fig. 2, e) are not very different in form from the laiger, but 

 are usually somewhat more rounded in their curvatures, and 

 slightly more contort. Both kinds are plentifully scattered 

 through all parts of the interior. The larger, which are the 

 less numerous, vary from 22 to 30/x in length, and attain a 

 maximum stoutness of 3/x; the smaller are only from 9 to 13/u 

 long, and never more than Ifj. in diameter. 



Loc. — Off Norah Head, coast of New South Wales. 



REFERENCE LIST OF LITERATURE. 

 L Annandale, N. — "Some Sponges parasitic on Clionidte, with farther 

 Notes on that Famil3\"' Rec. Indian Mus., xi., Part vi., 19lo, p. 4(14, 

 PI. xxxiv., fig. 3, text-fig. 3. 



2. Carter, H. J. — " Descriptions and Figures of Deep-Sea Sponges and 



their Spicules, from the Atlantic Ocean, dredged up on board 

 H.M.S. 'Porcupine,' chieflj^ in 1869 (concluded). "" Aim. Mag. Nat. 

 Hist., (4), xviii., 187H; (a) p.238, PI. xv., tig. 43; (/>) p.289, PI. xvi., 

 fig. 5 1. 



3. Dendy, a. — " Report on the Sponges collected bj^ Prof. Herdman at 



Ceylon in 1902." Reports on the Pearl Oj^ster Fisheries in the 

 (lulf of Manaar, Vol. iii., 190,"), p. 180, PI. xii., fig. 10. 



4. Kallmann, E. F. — "A Revision of the Genera with Microscleres in- 



cluded, or provisionally included in the Family' Axinellid*; with 

 Descriptions of some Australian Species." Proc. Linn. Soc. N. S. 

 Wales, 191H, Vol. xH., Part 3, pp. 520, 543. 



5. TuiELK, J. — " Studien iiher pazitischc Spongien." Zoologica, 1898, 



Heft. 24, pp.59, GO. 



