FROM THE AUSTRALIAN TERTIARIES. 



415 



the median area is crowded with nearly straight ridge-like costs?, 

 passing from the bases of the primaries almost transversely, and 

 carrying small secondaries. Interradia with two vertical rows of 

 primaries of the same size and structure as those of the ambulacra, 

 their scrobicules raised and united with those above and below by 

 vertical straight costse, and with those of the opposite row by 

 numerous crowded, transverse, straight costse, with small secondaries 

 on them. Peristome small, almost without cuts. 



Ortholophus lixeatus, Dune. (See the description of the species 

 under the generic head of Temnechinus, Quart. Journ. Geol. 

 Soc. vol. xxxiii. p. 46.) 



The dimensions of the specimen are : height 8 millim., diameter 

 14 millim., width of apical system 4 millim. 



The alliance of this form is closest to the recent Trigonocidaris, 

 A. Ag., and it is the representative of the Dietyopleuri of the 

 Tertiaries of Sind, Kach, and Egypt. 



7. Paradoxechixus xovus, Laube *. 



The impressions left by the basal and radial plates upon the test 

 close to the anal margin indicate that the last-named plates were 

 placed between the others, and that they all entered the anal ring ; 

 the anal opening was large, and the apical system appears to be de- 

 pressed according to Laube's evidently correct drawing of the species. 

 The height of the test is 6*5 millim., the diameter 13 millim., and 

 the diameter of the anal opening 7 millim., whilst that of the 

 peristome is only 4 millim. The pairs of pores are on the plates of 

 the test, and not upon costse, and the oblique direction of the zigzag 

 of bunches of costse is very striking ; the primary tubercles are 

 neither crenulate nor perforate. The branchial cuts are very small. 

 This is a well-defined genus and species, and if the statement about 

 the apical system just made turns out to be absolutely correct, then 

 the alliance is with the Eocene Dietyopleuri of Sind and of Egypt. 

 Cotteau has defined a genus, Coptechinus (" Ech. nouv. ou peu 

 connus," Extr. du Bull, de la Soc. Zool. de Erance, 1884, fasc. 2, 

 p. 27), and the species is from the Miocene of Erance ; but' the fo m 

 so well described is clearly a species of Paradoceechinus, that genus 

 having escaped the observation of the distinguished Erench Echino- 

 dermatist. It is ver} r interesting to be able to trace this westerly 

 development of an Australian genus. Paradoocecliinus novus was 

 found in the deposits of the Murray Cliffs, South Australia. 



8. Clypeaster folium:, Agass. Cat. rais. p. 73; Desor, Synopsis, 



p. 243. 



A variety, var. elongata. 



So long ago as 1864 I asserted the presence of Clypeaster folium, 

 Agassiz, in the Murray Cliffs and at Mount Gambier, South Australia 

 (Ann. & Mag. Nat. Hist. 1864, vol. xiv. p. 166). But Mr. E. 

 Etheridge, jun., in his communication to this Society in 1875, 



* Tom. cit. p. 186, fig. 2. 



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