Si/riopsis of the Australian Calcarea Heterocada. ]()] 



the a[)ical ray is often absent. (2) Triradiates of tlie main 

 skeleton ; varying from nearly regular to slight!}' sagittal ; 

 with ver}- long, slender, straight or slightly curved rays, 

 sharply pointed and measuring about Oo'i by 0()](j nma. 

 These spicules ai-e veiy irregularly arranged but many of 

 them have one ray pointing centrifugal!}^ towards the dermal 

 surface. In many of them a small apical ray is developed. 

 (3) Triradiates of the dermal surface ; similar to the fore- 

 going but decidedly smaller ; arranged parallel to the surface 

 to form a thin dermal cortex, (i) .Large dermal oxea ; 

 rather slender, fusiform, symmetrical, very slightly curved, 

 gradually sharp-pointed at each end; measuring about 1 '4 

 by 03 mm.; occasionally however they are much largei- 

 and they may then have a hastately pointed inner end. 

 These spicules are scattered singly and irregularly at right 

 angles to the dermal surface, with the outer end projecting 

 for a short distance. (5) Long, fine, hair-like oxea'; these 

 are arranged in loose, iri-egular, scattered bundles between 

 the large oxea and they also form the feebly developed 

 oscular fringe. 



Locality.— ^e-Av Port Phillip Heads (coll. J. B. Wilson). 



42. Leucandra gladiator, n. sp. 



The single specimen in the collection forms an extremely 

 irregular, contorted crust, with a number of deeply convex 

 surfaces, bordered by prominent margins, as if it had grown 

 over some irregularly cylindrical body. A few small oscula 

 are irregularly scattered over the convex upper surface. The 

 surface is slightly hispid, the hispid character becoming 

 mucli more strongly developed at the margins of the crust. 

 The .specimen has been broken, but it must have Ijeen about 

 50 nan. in greatest diameter. The growth has been 

 extremely irregular, and it has enclosed various foreign 

 objects. The texture is coarse and fragile. The dei'mal 

 cortex is strong, but not very thick. 



The canal-system is difficult to work out in detail, owing 

 to the strong development of the skeleton, wdiich renders 

 section-cutting very difficult. There is no large, ct.;ntral, 

 gastral cavity, but a number of tolerably wide exhalant 

 canals converge towards each osculum. The flagellated 

 chambers are irregularly scattered, approximately sjiherical, 

 and about 09 mm. in diameter. 



The skeleton is composed of the following spicules : — (!) 

 Gastral quadriradiates; minute, cruciform or dagger-sha[>ed ; 



