DENDY— HOMOSCLEROPHORA AND ASTROTETRAXONIDA 247 



O'OOl mm. in diameter at base, but may be reduced to a mere knob (fig. 2 b"). These 

 spicules are very rare in the boiled out preparations, but paraffin sections show them in 

 considerable numbers piercing the cortex and usually projecting freely from the surface, 

 where their cladomes are generally broken off". 



(3) Oxea (fig. 2 c, 2 c'). Very slightly curved, usually gradually and finely pointed 

 at each end ; measuring up to about 0*84 by 0'02 mm., but varying a good deal, both in 

 length and diameter, apd often very slender. 



(4) Large spherasters (fig. 2 d) ; with large centrum and generally sharp-pointed, 

 conical rays, usually more or less roughened on their sides, especially towards the apex ; 

 total diameter about 0"04 mm., with rays about 0"008 mm. long. Very numerous, 

 especially in the cortex. Occasionally the rays are all blunted and roughened at the 

 ends, very much as in Hentschel's Auro7-a [Stelletta) aurora [1909]. 



(5) Small spherastei"s and oxyasters (fig. 2e); total diameter about O'OOS to 

 0"02 mm., variable. Some of these are probably early stages of the large spheraster, 

 but I doubt if this is the case with all. 



(6) Oxyasters (fig. 2/) ; rather large, with straight, moderately stout rays, about 

 6 or 8 in number and usually more or less roughened. Sometimes there is a small but 

 distinct centrum. Total diameter of spicule about 0'07 mm. 



This species is evidently related not distantly to Carter's Aurora (Stelletta) globo- 

 stellata from Ceylon [1883 b], which has never been satisfactorily described. I have two 

 preparations in Mr Carter's cabinet, evidently made from the type, though labelled 

 " Stelletta globostellifera." From an examination of these I find that the principal points 

 in which Carter's spepies differs from Aurora providentice are as follows : — (l) The large 

 spheraster has a somewhat smaller centrum and the rays are rather longer, smooth, and 

 often blunted at the ends ; (2) The large oxyaster is represented by a smaller spicule with 

 long and very slender rays (apparently the "chiaster" of Sollas's description [1888] but 

 reaching a total diameter of 0'045 mm., whereas Sollas gives 0"015 mm.). I have found 

 no anatrisenes, but these are so minute and the cladomes are so easily broken off in the 

 " Sealark " species that I cannot attribute any great importance to their apparent absence 

 in A. globostellata. Sollas gives an " orthodragma " as a constituent of the spiculation in 

 A. globostellata, but I can find none in Carter's slides nor does Carter himself mention it, 

 so we must suppose that Sollas has made a mistake in this respect. He does not say how 

 he obtained his information. 



It is also evident that our species is related to Hentschel's Aurora [Stelletta) aurora, 

 from S.W. Australia, but the details of spiculation afford quite sufficient differences to 

 separate the two. 



Register No., Locality, &c. Lxxxvi. 2, Providence, 4.10.05, D. 4, 50 — 78 fathoms. 



11. Aurora cribriporosa n. sp. 



(Plate 44, fig. 4 ; Plate 46, fig. 3.) 



The single specimen (Plate 44, fig. 4) has a broad, oval base of attachment, from 

 which it rises up on all sides like a hillock, culminating in a somewhat excentrically 



