REPORT ON THE OPHIUROIDEA. 13 



occupying the outer lateral corners of the mouth shiekl. Under arm plates wider than 

 long, with a rounded, truncated angle within ; slight re-entering curves on the lateral sides 

 and the outer edge curved. Side arm plates short and thick, with cleanly curved outer 

 margin ; separated above by the large upper arm plates which are much broader than long, 

 and strongly arched with outer side straight, except at the coi*ners where it is rounded ; 

 length to breadth, 4 "5 : 1'3. Disk thick but flat, with a notch over the arms ; it is covered, 

 including radial shields and space next mouth papillae, with an even, fine granulation ; 

 thirteen grains in 1 mm. long. Genital openings long, extending from outer edge 

 of mouth shield nearly to margin of disk. Ten short, flat arm spines with rounded 

 ends, about two-thirds as long as a side arm plate, except the lowest which is longer and 

 larger. Two s'^all, round tentacle scales, whereof one covers the base of the lowest arm 

 spine. Colour in alcohol, nearly white. 



Station 219.— March 10, 1875 ; north-east of New Guinea; lat. 1° 50' S., long. 146° 

 42' E. ; 150 fathoms ; mud. 



This species agrees in the number of disk grains with Ophio2oeza yoldii, but has 

 twice as many arm spines. Ophiopeza fallax, and OpJuoj^eza aster agree with each 

 other as to grains (about twenty-five in the length of 1 mm.) Ophiopeza aster, 

 however, has six arm spines, instead of eight, and the entire mouth angle, including 

 mouth shield, is closely granulated. Finally, Ophiopeza petersi has about eighteen 

 grains in the length of 1 mm., six arm spines, and naked radial shields. 



Species of Opluopeza not herein described. 



Ophiopteza fallax, Pet. (PL XLI. figs. 1-3). 



Ophiopeza fallax, Pet., Monatsb. Konig. Akad. Berlin, p. 465, 18-51 ; Wiegmann's Archiv, 

 p. 84, 1852. 



Great Ocean. 



Ophiopeza petersi, Lym., Bull. Mus. Comp. Zool., vol. v., part 9, p. 217, pi. ii. figs. 

 22-24, 1878. 



West Indies; 177 fathoms. 



Pectinura. 

 Pectinura, Fbs., Linn. Trans., vol. xlx., 1842. 



Disk granulated. Teeth, and numerous even, close-set mouth papillge ; no tooth 

 papillse. Spines smooth, shorter than the arm joints, numerous (5-15). Tentacle scales, 

 rarely one, usually two, in which case the upper one overlaps the base of the lowest arm 

 spine. An indentation in the back of the disk at the base of each arm. A supplementary 



