r.Y E. F. HALLMANF. 4-77 



the typiciil variety, wliile those of the branches are difterent only 

 in the fact that their extremities are most frequently more or 

 less blunt-pointed, and strongylote f^rins are common. The 

 branch-spicules are of the same dimensions in all three specimens, 

 I'anging in length from about 170 to slightly above 300// and 

 attaining to about !)/i in stoutness: the stalk-spicules have a 

 maximum size, in the type-specimen, of (rarely) 480 x 15/a; in 

 R.N. 1046, of 450 X 17//.; and in R.N. 415, of 40o x 14//.. 



The spiruhe are not distinguishable from those of the typical 

 variety. JVLicrostrongyla are rather scarce in R.N. 415, and in 

 the other two specimens are extremei}^ rare or absent; apparently 

 they are never centrotylote, and are at most 15x."5/><. in size. 

 Abnormal forms of the microstrongyla, such as occur in the 

 typical variety, were not observed. 



Thaciivcladus digitatus var. strongvlatus, var.nov. 

 (PL xxii., fig. 5; PI. xxiii., fig. 4; i'l.xxvi., figs.:;,G; PI. x.xvii. tig. 4.) 



Dmiiiums. — Branches cylindrical, untapered, moderately 

 slendei'. Oscula irregularly scattered. Dermal membrane with 

 closely packed spiruhe confined to a superficial layer seldom as 

 much as 25/ji in thickness. Radial fibres of lesser length than 

 the diameter of the axial fune. Megascleres chiefly strongyla 

 and ver}' blunt-pointed oxea, — those in the branches rarely ex 

 ceeding 290 by 7/^ in size. 



i,oc.— Port Phillip. 

 ^ This variety is represented by a single incomplete (but ex- 

 cellently preserved) example (PI. xxii., fig. 5) — consisting only of 

 a pair of united branches — the appearance (of the proximal part) 

 of which suggests its having grown from a small broken-oli' piece 

 of another specimen. As compared with the representatives of 

 the preceding varieties, the specimen is distinguished chiefly by 

 the more or less strongylote character of the majority of its 

 megascleres — in which respect it rather resembles an example of 

 T. rfte'porosiif;: this statement, however, is possibly true only as 

 regards the megascleres of the branches, since a stalk is lacking. 

 The branches are cylindrical and slender, 3-5 to 5mm. in diameter. 



