REPORT ON THE ASTEROIDEA. 269 



Its range of depth varies from 20 fathoms to 640 fathoms; the latter depth being off the 

 North American coast (Verrill). 



3. Pentagonaster astrologorum (Mtiller and Troschel), Perrier. 



Astrogonium astrologorum, Miiller and Troschel, 1842, System der Asteriden, p. 54. 



Pentagonaster (?) astrologorum, Gray, 1866, Synop. Spec. Starf. Brit. Mus., p. 11. 



Pentagonaster astrologorum, Perrier, 1876, ReVis. Stell. Mus., p.196 (Archives de Zool. expeV., t.v. p. 12). 



Locality. — Sydney Harbour. 



4. Pentagonaster patagonicns, n. sp. (PL XLVI. figs. 3 and 4 ; PI. XLIX. figs. 3 



and 4). 



Rays five. R = 68 mm. ; r=43 mm. R=l - 58 r. The minor radius is thus in the 

 proportion of about 63 per cent. 



Body of large size. General form depressed and fiat. Abactinal area slightly inflated 

 in the central region and flexible. Marginal contour pentagonal with a slight stellate 

 tendency, the extremities of the rays being pointed and slightly produced. Interbrachial 

 arcs forming a distinct curve sweeping from tip to tip. Margin thick and more or less 

 vertical, the rounding more bevelled on the abactinal surface than on the actinal. 



The whole abactinal paxillar area is covered with small, regular, polygonal tabula or 

 paxillae, those in the radial areas regularly hexagonal and larger than those in the inter- 

 mediate regions, which are rhomboid, and all diminish in size as they approach the margin. 

 The larger paxillae in the radial regions do not actually touch one another but are slightly 

 spaced apart. These paxillae consist of a hexagonal tabulum on a low broad base, and 

 the tabulum is covered with low truncate granules, the marginal series of which are slightly 

 larger than the rest and sub-prismatic or polygonal ; all the granules are uniformly trun- 

 cate so as to form a smooth upper surface to the tabulum, which is also slightly convex ; 

 and the edges of the paxillae are sharply cut as if "dressed" with a knife. Occasional 

 paxillae at wide intervals apart bear a single small excavate pedicellaria, having two chisel- 

 shaped or spatulate jaws, which can be drawn down more or less into the pit or cavity ; 

 the form of the jaws varies considerably, sometimes being narrow and elongate, sometimes 

 much broader and more lamelliform ; occasionally three jaws may be present. The small 

 rhomboid tabula in the interradial regions, which are crowded and fit close to one another, 

 have a much lower base ; indeed the base appears to gradually diminish and the paxillar 

 character to disappear as the tabula approach the margin. In the marginal region, where 

 the tabula are smaller, faintly indicated lines may be seen to proceed inwards from the 

 sutures of the supero-marginal plates, which have the appearance of dividing up this 

 marginal series of small tabula into band-like series corresponding in breadth to the length 

 of the marginal plates, four or five rows of tabula being in each band ; this character is 

 lost, however, as soon as the large hexagonal and separated paxillae are reached. There 



