214 



•ENDEAVOUE" SCIENTIFIC RESULTS. 



Megasclcrcs. — 



(i.) Jlie principal styli are sub-conical and slightly curved 

 spicules, occasionally exhibiting a faint sub-basal 

 constriction, and attaining a maximum size of 320 

 X 10 yi. Although the smallest of them are hidis- 

 tinguishable from the largest accessory styli ; the 

 lower limit of their length may be fixed at about 

 120 ]i, since neither do individuals of lesser length 

 than this exhibit the curvature of form typical of the 

 principal spicules; nor individuals of greater length, 

 the minute spination typical of the accessory. Their 

 only inequality of surface is an obscure ruggedness 

 which, in the case of the shorter spicules, may affect 

 the entire surface, but which becomes less and less 

 distinct and more restricted to the basal region as the 

 length of the spicule increases, and finally dis- 

 appejjrs ; spicules of greater length than 180 n are, 

 with rare exceptions, quite smooth. 



(ii.) The accessory acanthostyles are straight sub-conical 

 spicules, frequently with a. slight basal enlargement 

 (subtylote) and with a minutely spined or, less fre- 

 quently, merely rugged surface. Their length varies 

 from about 40 to 120 |(, but seldom exceeds 95 jx ; 

 they are rarely more than 5 ]i in diameter. 



(iii.) The auxiliary spicules are straight subt}lostyli (or 

 tylostyli) varying in length from 190 to 390 \i, and in 

 diameter up to 5 }i. They sometimes show an obscure 

 spination of the extreme basal end. 



Microscleres : Toxa of two kinds. — 



(i.) Shorter, typically tricurvate forms, with well-arched 

 median flexure ; rarely, angulately bent and with 

 straight arms. They range from less than 20 n to 

 upwards of 100 \i (rarely more than 90 p) in length, 

 and up to 3 /t in diameter, 

 (ii.) Extremely rare, long slender forms, ^ with fairly 

 straight arms, ranging in length from 150 /i or less 

 to at least 275 ;/, and in diameter up to 1.5 ji. The 

 shortest make some approach in form to the first- 

 mentioned and indicate that the two forms are modi- 

 fications of a single original form. 

 l^ocs. — Tasmania (Austr. Mus. Coll.); forty miles west 

 from Kingston, South Australia, 30 fnis. ; fifteen miles east- 

 north-east from Cape Barren, Tasmania, 53 Fms. ("Endea- 

 vour"). 



1 Owing to their raritv these toxa were at first overlooked, and have 

 consequently been omitted from the text-figure. Their presence would 

 have remained unsuspected had not the existence of similar spicules in 

 the closely allied C- inanchorta prompted me to undertake a special search 

 for them. 



