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"ENDEAVOUR" SCIENTIFIC EESULTS. 



The dermal skeleton consists of acanthostyles and oxea. 

 The proportion in which each occurs is variable, but the 

 smooth spicules are always present, and in places — particu- 

 larly where the membrane overlies large subdermal spaces — 

 are more numerous than the spined spicules. Occasionally, 

 over small areas, an approach to the reticulate arrangement is 

 met with ; or the acanthostyles may be clustered in small 

 patches so as to give a mottled appearance, but there is never 

 (in any observed case) a parallel arrangement of spicules to 

 form the sides of meshes of a distinct reticulation such as is 

 found in the varieties areuacea and levis. 



Megasclere.s. — 



(i.) The oxea vary in length from i6o to 

 220 ^ ; the stoutest are probably 

 never more than 4.5 {i in diameter. 

 The characteristic end-flexure is 

 only of occasional occurrence, it 

 may, however, be developed quite as 

 highly as in any of the other 

 varieties, as the spicule shown in 

 Text-figure 29 bears witness. The 

 oxea are characterised in compari- 

 son \\ith those of the other varieties 

 by a slight elongated subterminal 

 constriction which occurs at both 

 ends. In this respect the spicules 

 resemble those of Clathrissa arbiis- 

 cula. The feature is occasionally 

 observed in the spicules of some of 

 the other varieties of Crella incrus- 

 tans but is never so \\'ell marked as 

 in the present one. 



(ii.) The principal acanthostyles reach a 

 maximum size 'Of 170 x 9 f(. 



Fig. 29— ('. in- 

 crustans var. di- 

 gitata. a Oxea 

 (showing the ex- 

 treme of asym- 

 metry in these 

 spicules), b Iso- 

 chela arcuata. 



(iii.) The dermal acanthostyles var} m 

 length from 60 to 90 ]i ; the stoutest 

 are 7 or 8 \i in diameter. \^ery rarely acanthoxea are 

 met with in the dermal skeleton ; these are sometimes 

 OA"er 100 \i in length. 



Microscleres. — 



The chelaj, which \ary in length from 13 to 20.5 /(, but are 



rarely more than 18 /«, show a scarcely appreciable 



differentiation into two forms. 



As alreadv pointed out this variety is probably identical w ith 



the tvpical variety which comes from Port Phillip. But there 



I 



