^ev (lull liiire Fossils. 179 



jjlace oil the calcaieoiis iiitciiKxlrs.i Tin- si>irulrs (selerodei-mitesj of 

 Mopsed are stated to Ije cluh-sliape(l,2 l)ut tlie majority of those 

 figured in the " Challenger " report and from tlie " Thetis " 

 expedition are spindle-sliaped. thontrh sdinetimes a])proa(hing the 

 clavate type. 



In Melifoden the internodes are calcareous with a horny matrix. 

 In the present examples referred to Mopsen. the microscopic struc- 

 ture of the joints excludes that genus from considei'ation. since tlicy 

 are seen to be solidly and originally calcified. 



There is, however, at least one species in the present collection 

 Avhich agrees with /.v«s, as seen in the long, and coarsely-grooved 

 joints, and the dense lamellated structure of the axis. 



CRIXOIDEA. 



Fam. COMATULIDAE. 



Genus ANTEDON. de Freminville. 



Antkdon pkotomackonema, sp. nov. (Plate XVII., Fi.us. 18a, h). 



Description. — Isolated centrodorsal nearly hemispherical seen 

 from the side; with more than 30 cirrus sockets, an-anged in threes 

 and fours vertically, alternate; borders of sockets prominent, with 

 indications of a crenulated surface to the rim. Ventral aspect sub- 

 circular, showing the grooves of the radial pentagon, which increase 

 in width near the periphery. Dorsal aspect subpentagonal at base, 

 with a central depression apparently not perforate or permanently 

 open. 



Dimensions. — Type: Height of centrodoi'sal, 1.154 mm; width 

 ventrally. 1.7 mm. 



Ohservations. — Another specimen, probably of this species, and 

 twice the dimensions, occurs in the same sample, viz.. Bore 11, 

 430-432 feet. It is. however, not so well preserved, and conse- 

 quently is not figured. 



Separate brachial ossicles, which may be referable to this or an 

 allied species, are common in the Mallee borings, in the Janjukian 

 series, having a Mount Gambier facies; and also at Batesford, 

 Geelong.3 



There is still another species of Antedon in the southern Austra- 

 lian Tertiaries, which is found at Torquay, Victoria, and at Mount 

 ■Gambier. This will be described later, from specimens in the 



1. Wright and Studer, Rep. Chall., Zool.. vol. xxxi., 1889, Aloyonsria, p. 43. 



2. Cambridge Natural History, Coelenterata, 1906, p. 3.53. 



3. See I'roc. Roy. .Soc. Victoria, vol. xxii. (N.S.), pt. ii., 1910, pi. 30;., p. lii., fijjg. 8a-//. 



