Prof. S. Loven on the Structure of the EcMnoidea. 427 



attached to the soft dorsal ; three anal spines. Caudal rounded. 

 Pectoral short, rounded. Scales rather large, finely ctenoid. 



It is more difficult to come to a final decision as regards the 

 specific affinity of Psammoperca waigiensis and Gnidon chi- 

 nensis. The British Museum possesses now six examples : — 



1. The typical example, stufied, from Australia (9 inches). 



2. A stuffed example from Victoria (7 inches). 



3. An example in spirits from New South Wales (9 inches). 



4. A stuffed example from Torres Straits (12 inches). 



5. An example in spirits from Manila (10 inches); obtained 

 by Dr. A. B. Meyer, and undoubtedly identical with Gnidon 

 chinensis. 



6. A dry skin, said to be from China, obtained from a dealer 

 (10 inches long). 



In all these specimens the formula of the fins is the same : 

 the first dorsal has only seven spines, not eight*, the eighth 

 spine belonging to the second dorsal fin. In other respects 

 nearly every one of the specimens shows certain peculiarities, 

 so that no two agree perfectly with one another, not even those 

 from South Australia; but I think these differences are so 

 slight as not to allow of specific distinction. Thus the number 

 of scales in the lateral line varies from forty-seven to fifty-five ; 

 the vertical fins are sometimes quite naked, sometimes more or 

 less thinly covered with minute scales ; the humerus has some- 

 times two short points behind, sometimes one of the points is 

 slightly denticulated, sometimes the lower is absent altogether. 

 There is only one point by which the Philippine specimen is 

 somewhat more conspicuously distinguished ; and that is the 

 distinctly concave profile of the snout ; but also in this res])ect 

 it is approached by that of our Australian example which is 

 preserved in spirits, although the concavity is so slight that it 

 has been entirely effaced in the stuffed specimens. 



Under these circumstances I am inclined to regard these 

 fishes as specifically identical. 



LXII. — On the Structure of the EcMnoidea. By S. Loven. 

 [Concluded from p. 385,] 



The same arrangement that is expressed by the formula for 

 the two series of the ambulacral peristomial plates, makes itself 

 apparent also in the appearance of the sph^eridia. In the Spa- 

 tangidge (for example, Brissopsis lyrifera) they first show tliem- 

 selves in the one-pored peristomial plate in each ambulacrum, 

 quite close to the suture, and usually incline over towards the 



* What I have formerly (in dried specimens) taken for the spine of the 

 second dorsal fin is, in fact, only the hardened first simple rav. 



30* 



