THE RECENT CRINOIDS OP AUSTRALIA — CLARK. 765 



Antedon decipiens, 1884, Bell, Rep. Zool. Coll. H.M.S. " Alert," 

 p. 159, pi. xi., figs. B, Ba (Arafura Sea, 32-36 fms.), 



Antedon irregularis, 1884, Bell, torn, cit., p. 161, pi. xiii., figs. 

 A, Aa-G (Prince op Wales Channel ; Torres Strait). 



Differential Characters. — Atnphimetra variipiyma is easily dis- 

 tinguished from all other Australian Cornatulids ; it always has 

 more than ten arms, usually from fifteen to twenty, with short 

 discoidal brachials distally ; the division series and arm bases are 

 rugged and tubei'culous ; the long lower pinnules have segments 

 with the distal corners produced into broad rounded processes so 

 that the outline of the pinnules is strongly serrate. 



Specimen in the Australian Museum Collection. — Mast Head 

 Island — One fine twenty-two armed specimen. Ten miles south- 

 west of Mapoon, 10 fathoms — Three tine specimens ; one has 

 nineteen arms 150 mm. long and cirri xvi., 41-43, 25 mm. to 30 

 mm. long ; another has twenty-one arms 150 mm. long and cirri 

 30 mm. long with 40-42 segments ; the third has seventeen arms 

 130 mm. long and cirri xxiii., 41-44, 30 mm. long. In these 

 specimens the processes on the segments of the lower pinnules 

 are strongly developed and typical ; the cirri are more or less 

 carinate distally, and the synarthrial tubercles are prominent so 

 that the animals are characteristically rugose. Port Curtis — 

 Two specimens ; one has fourteen arms 80 mm. long and cirri 

 xxiii., 35-40, 30 mm. long; the other has twenty-six arms 100 

 mm. long and cirri xxix., 35-45 (usually 40-41) 30 mm long ; the 

 centrodorsal is 5 mm. in diameter at the dorsal pole ; the arm 

 bases are exceptionally rugged with the synarthrial tubercles 

 large, prominent, and bluntly conical ; the lower brachials are 

 very short but much swollen with strongly projecting distal 

 edges ; the division series are just in opposition laterally ; the 

 distal cirrus segments are very strongly and sharply carinate, 

 this carination standing out as a broad spine of wliicli the outer 

 edge is almost or quite parallel to the longitudinal axes of the 

 segments. 



Additional Australian Records. — Prince of Wales Channel, in 

 7 fathoms, in 8 fathoms, and in 7-9 fathoms ; Torres Strait, in 

 5-7 fathoms, and in 10 fathoms ; Holothuria Bank, in 24, and in 

 3& fathoms; North-east of Holothuria Bank, in 15-20 fathoms ; 

 Dundas Strait, in 17 fathoms ; Baudin Island. 



Distribution. — Mergui Archipelago, Singapore, Canton, and 

 the Piiilippine Islands southward to Australia, reaching, on the 

 east coast. Port Curtis, Queensland.* 



* Mr. H. C. Chadwick has recorded this species from Ceylon, but such 

 of his specimens as I have examined prove to be Hcterometra reynaudii. 



