A MONOGRAPH OF THE EXISTING CRINOIDS 385 



localities given are correct with the single exception of North Borneo, which refers 

 to Grube's Comatula laevissima (—molleri). 



In 1919 Dr. Torsten GislGn said that he entirely agreed with Reichensperger's 

 opinion that it is incorrect to maintain milberti (=tessellata) and discoidea as species 

 on the basis of the somewhat different cirrals. 



AMPHIMETRA TESSELLATA PAPUENSIS A. H. Clark 



[See vol. 1, pt. 2, figs. 37, 38 (radial pentagon), p. 20.] 



Amphimetra discoidea (part) A. H. Clark, Die Fauna Sudwest-Australiens, vol. 3, Lief. 13, 1911, 

 p. 549 (specimens from Port Moresby and Hood lagoon, New Guinea). 



Amphimetra schlegelii (part) A. H. Clark, Crinoids of the Indian Ocean, 1912, p. Ill (New Guinea; 

 Tonga; Fiji). 



A?nphimetra papuensis A. H. Clark, Smithsonian Misc. Coll., vol. 61, No. 15, 191.3, p. 25 (Tonga 

 and Fiji; characters of the cirri; also Hood lagoon and Port Moresby, New Guinea); Unstalked 

 crinoids of the Siboga-Expcd., 1918, p. 83 (in key; range), p. 89 (references; localities from which 

 known). — Gisl£n, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 48 (ex- 

 tends to Tonga). 



Diagnostic features. — A medium-sized or rather small form with the cirri moderately 

 stout and more or less straight basally but becoming slender and recurved distally, 

 with 30-34 segments of which the longest are usually about as long as broad and the 

 short outer bear prominent long, slender, and sharp dorsal spines; the arms are up 

 to 110 mm. in length; synarthrial tubercles are obsolete; the proximal pinnules are 

 slender, with 17 or 18 segments. 



Description. — The centrodorsal is discoidal, rather thin, with the small irregular 

 dorsal pole flat and finely pitted. The cirri are arranged in two closely crowded 

 and somewhat irregularly alternating rows. 



The cirri are XVII, 30-34, about 30 mm. long. The first segment is very short, 

 three to four times as broad as long, and those following slowly increase in length 

 to from the fifth-eight to the ninth-eleventh segments, which are usually about as 

 long as broad or slightly broader than long but vary from half again as broad as long 

 to slightly longer than broad. The distal segments are between half again and twice 

 as broad as long, the terminal gradually lengthening again so that the last two or 

 three are about as long as broad. The cirri are moderately stout basally, tapering 

 very slowly in the proximal half but more rapidly in the distal half, so that the width 

 of the terminal segments is not much more than half that of the basal segments. 

 From the ninth- thirteenth segment onward long, sharp, and conspicuous dorsal spines 

 are developed. 



The radials are rather long, twice as long laterally as in the median line, with the 

 distal border strongly and regularly concave. The sides of the radial pentagon are 

 parallel. The IBrj are about three times as long as the radials in the median fine, 

 rather short, between five and six times as broad as long, with the distal border 

 slightly and very broadly concave in the middle and at the ends straight or very 

 slightly and broadly curved downward. The lateral portions of the dorsal surface 

 are flattened or slightly and broadly swollen, and the lateral edges are throughout in 

 lateral apposition and are rather broadly flattened. The IBr 2 (axillaries) are low, 

 between two and one-half and three times as broad as long, about twice as long as 

 the IBri, triangular with the lateral angles rather broadly truncated and the corners 



