REPORT ON THE OPHIUROTDEA. 53 



Ophioghjpha hrevispina (?), E. A. Smith. 



Oplnorihjpha hrevispina, E. A. Smith, Ann. Mag. Nat. Hist., vol. xvii. p. 112, Feb. 1876; 

 Transit of Venus Expedition, p. 11, pi. xvii. figs. 5a, c. — Lyni., Bull. Mus. Comp. ZooL, 

 vol. v., part 7, p. 78, pL ii figs. 44-46, 



Thi-ee short, blunt, peg-like arm spines, evenly spaced. PapiUse of arm comb short, 

 close set, and sharp. Disk scales of moderate size, thick and swollen. Very small, 

 narrow side mouth shields. 



(Ty|)e specimen from Royal Sound, Kerguelen.) Diameter of disk 11 mm. Length 

 of arm 45 mm. Width of arm 2*5 mm. Mouth papillse short, blunt, close set, four or 

 five on each side, and two longer at apex of jaw. Mouth .shield pentagonal, with a blunt 

 angle inward, outer edge curved, lateral sides notched ; length to breadth, 2"3 : 2. Side 

 mouth shields extending along inner angle of mouth shield, narrow, of about even width, 

 meeting within. First under arm plate very large, broader than long, transverse oval in 

 shape ; next three plates wider without than within, their sides straight, except the outer, 

 which is curved ; the rest are triangular, with outer edge curved, and an angle within. 

 Side arm plates short, slightly swollen, just meeting below beyond the disk ; widely 

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

 wider without than within, with outer side curved and inner side re-enteringly curved. 

 The upper surface of disk has numerous rounded, much swollen plates, closely soldered 

 together, with a cluster of six primaries in the centre separated by one or two rows of 

 smaller plates ; outside this cluster in each interbrachial space is another large rounded 

 plate. Radial shields longer than broad, much rounded, their inner ends slightly smaller 

 than the outer, and widely separated by a large rounded triangular plate within and smaller 

 scales without ; length to breadth 2 : 1 '5. Interbrachial space below evenly covered by small 

 thick scales. The genital scale is nearly or quite covered, except at its outer portion, 

 whose free edge carries a row of very fine saw-like papillae, which become a little longer 

 above, where they make the arm comb. Three small blunt arm spines, equally spaced, 

 and standing low on the outer edge of side arm plate. The pores of the mouth tentacles 

 have four or five close-set, small, tooth-like scales on each side ; the second and third set 

 have four or five on the interbrachial side, and three on the brachial ; beyond this they 

 diminish till a short distance beyond the disk, where there is on the inner side a small 

 scale, similar to and continuous mth the arm spines, and on the outer side a little ridge. 

 Colour in alcohol, light grey. 



Mr. Smith, who kindly compared a Challenger specimen with his originals, reports 

 that the latter are smaller, and differ from the former in having disk scales coarser, 

 radial shields that converge and touch each other, upper arm plates narrower inward, &c. 

 As these difierences may depend on age, I have retained the name with a query. 



