12 N CLARK: CRINOID FAMILY ANTEDONIDAE 



Bathymetkin \i:: Orthometra (nov.), Tonrometra (nov.), Fariometra 

 (nov.), Trichometra, Hathrometra, Nepio?netra (nov.), Phrixometra 

 iiiov.), Thaumatometra, and Bathymetra. 



Dorometra, gen. nov. 



Genotype. Antedon nana Hartlaub, 1890. 



Diagnosis. — P 3 is much the longest and stoutest pinnule on the arm; 

 the cirri arc XX-XLV (rarely over XL), with not over 16 segments; 

 these have produced distal ends which overlap the proximal ends of 

 those succeeding, and the outer are much longer than their proximal 

 width; the size is small, the arms being from 23 mm. to 50 mm. long; 

 the brachials have smooth, or only very finely spinous, distal edges. 



Geographical Range. — Red Sea to Madagascar and Mauritius, east- 

 ward to northern Australia and the East Indies, and northward to 

 southern Japan. 



Bathy metrical Range. — From the shore line down to 106 meters. 



Included Species. — Dorometra nana (Hartlaub), Dorometra mauritiana 

 (A. II. Clark), Dorometra gracilis (A. H. Clark), Dorometra briseis (A. 

 H. Clark), Dorometra parvicirra (P. H. Carpenter), Dorometra aegyptica 

 (A; H. Clark), and Dorometra clymene (A. H. Clark). 



Andrometra, gen. nov. 



'linotype. — Antedon psyche A. H. Clark, 1908. 



Diagnosis. — P 2 is much longer than Pi, and longer than P 3 though 

 similar to the latter; the centrodorsal is more or less sharply conical. 



Geographical Range. — Andaman Islands to southern Japan. 



Bathymetrical Range.— From 54 to 201 (?250) meters. 



Included Species. — Andrometra psyche (A. H. Clark) and Andrometra 

 initial (A. H. Clark). 



Argyrometra, gen. nov. 



Genotype. — Iridometra crispa A. H. Clark, 1908. 



Diagnosis.— Centrodorsal conical, broader than high, almost com- 

 pletely covered with cirrus sockets which decrease in size toward the 

 apex; these are from LX to LXXX in number; cirri very fragile, with 

 12 17 more or less elongated segments; P 3 is of the same length and 

 character as the succeeding pinnules; Pi and P 2 , which may be longer 

 or shorter than the following pinnules, have 12-13 segments, and taper 

 evenly to a point; their component segments become progressively 

 elongated; the brachial structure resembles that of Antedon petasus; 

 the size is small, the arms being about 30 mm. in length. 



Geographical Range. Hawaiian Islands to northern New Zealand. 



Bathymetrical Range. From 108 to 293 meters. 



Included Species. Argyrometra crispa (A. H. Clark) and Argyro- 

 metra mortenst ni, nov. 



