80 ME. J. W. XIPKBY OX PEJIMIAX FISH AXD PLANTS. 



Pal^eonisctjs alius, Kirlcby. PI. IX, fig. 1. 



P. htus, Kirkby, Aunals of Xat. Hist. 3rd Series, vol. IX, 

 p. 268.* 



Greatest length 2-f- inches ; length of body 2 inches ; maximum 

 breadth rather more than 1 inch, or more than one-half of the 

 length of the body ; breadth of tail ^ inch ; head f inch long, and 

 the same in width. 



The general form of this fish is gibbons ; the tail is only 

 slightly heterocercal. The pectoral fins are small and slender ; 

 the ventrals, which are also small, are placed l^V inch from the 

 snout, and the anal is 1 iV from the same point ; the dorsal, which 

 is the most robust of the fins mentioned, is situated at a point 

 between the anal and the ventrals. The caudal is wide, and has 

 about 24 strong rays : both lobes of this fin, as well as the 

 anterior borders of the dorsal and anal, are protected by fulcral 

 scales, as in both the preceding species ; and in advance of the 

 fulcrals are the large " ecailles impaires," which so generally 

 accompany them. 



The scales of the flanks are of the same type as those of P. 

 varians, but are comparatively wider and shorter. They are 

 robust and smooth, except in having marginal lines of growth, 

 and are arranged in steeply sloping dorso-ventral series. 



The bones of the head are ornamented with the same kind of 

 rugulose sculpturing as that which characterizes P. varians. The 

 orbit is also large. 



I do not know of any species of Palmonisms that approaches 

 P. alius in its great relative width of body, although in general 

 form of scales, in fin- structure, and in ornamentation of the bones 

 of the head it differs little from the two preceding species. 



One or two examples of this species have been found in the 

 fish-bed of the Old Quarry, Eulwell. 



Pal^onisctjs angustus ? Agassis. 



Along with the Palcsonisci previously described has occurred a 

 specimen of what appears to be another species. It is chiefly 



* At the suggestion of Sir Philip Egerton, I adopt the term alius for this species, 

 lalns having been already applied to another species of Pakeoniscus. 



