Clark — A Revision of Thalassometridx and Himerometridx. 1 



spending joints mHimerometra; brachials all short, at first discoidal, then 

 more or less wedge-shaped, becoming very short and regularly discoidal 

 in the outer half of the arm as in Himerometra; synarthrial tubercles 

 j)r()minpnt, sometimes excessively developed. 



Pi small and slender, witli numerous sh< irt joints; Pj, P3, or both, elon- 

 gate, rather large basally, but tapering, and slender distally; tlie distal 

 ends of the outer joints may be produced into broad lateral expansions, 

 and the proximal joints may be carinate. 



Color (in spirits). — White to dark reddish brown, purple, or violet; 

 ashey gray, white, or pale flesh color blotched or banded with purple 

 (light or dark) or yellowish brown; pale flesh color, the perisome and 

 pinnules brown or deep violet. 



Distribution. — Ceylon to the Mergui Archipelago, Sumatra, and Singa- 

 pore, PortDenison, Port Molle, the Arafura Sea and Aru Islands, Ceram, 

 the Philippines, Borneo, and northward to Canton and Japan. 

 Depth. — Littoral, and down to at least 32, possibly 36 fathoms. 

 Though well marked in regard to the generic characters, the genus 

 Ampliimetra presents exceptional ditticulties in the elucidation of the in- 

 terrelations of its component sjiecies, and no satisfactory synopsis of them 

 has up to the present been published. The species at present known are: 

 Amphimetra anceps (P. H. Cari^enter) 

 " ensiformis (A. H. Clark) 



," laevissiina (J. Miiller) 



" milberti (J. Miiller) 



" moZZert (A. H. Clark) 



" producta (A. H. Clark) 



" schegelii (A. H. Clark) 



?" tessellata (J. MnWer) 



" variipinna (P. H. Carpenter). 



5. Himerometra A. H. Clark. 



The species belonging to this genus as restricted are : 



Himerometra bartschi A. H. Clark 



' ' crassipinna ( Hartlaub ) 



" kraejjelini (Hartlaub) 



" magnipinna A. H. Clark 



" martensi (Hartlaub) 



" persica A. H. Clark 



" robustipinna A. H. Clark 



?" philiberti (J. Miiller). 



6. Oligometra A. H. Clark. 

 The species of this genus are : 



Oligometra adeonse (Lamarck) Oligometra imbricata A. H. Clark 

 " bidens (Bell) " japonica (Hartlaub) 



" caribbea A. H. Clark " pinniformis (P. H. Carpenter) 



" • carpenteri {BeW) " pulchella A. U. Cl&vli 



" gracilicirra A. H. Clark " serripinna {F. H. Carpenter). 



