Holt and Calderwood — Report on the Rarer Fishes. 467 



obliquity in the anterior profile ; in two, including that shown in PI. xliii., fig. 2, 

 which appear to conform most closely to the ordinary type in the character alluded 

 to, the anterior profile is only moderately oblique, and the snout is consequently 

 somewhat obtuse, whereas in the two remaining examples it is somewhat sharp. 



There exist, moreover, other differences, which, were they associated with those 

 already mentioned, would present some difficulty to the systematist. It happens, 

 however, that they occur independently, since specimens which in some character 

 conform to one type, depart from it signally in another. 



To illustrate this more fully we have selected two examples for detailed 

 description and comparison : they may be termed respectively, A and B, the 

 former conforming in the contour of the snout to the normal condition illustrated 

 by the specimen shown in figure 2. 



Dimensions. 



A. B. 



Total length, 74-5 cm. 93-90 cm. 



Length of head, 15-9 13-80 



„ snout, 3-8 3-45 



„ eye 3'3 3-45 



,, praemaxilla, 4-9 4-50 



,, barbel 1-0 1-05 



Greatest height of body, 12-6 11-60 



,, ,, of head, 11-2 9-60 



,, width of ,, 7-2 6-60 



"Width of interorbital space, 5-6 4-55 



Distance from isthmus to vent, ..... 8-7 11-40 



Tip of snout to first dorsal fin, 15-9 14-30 



,, „ to vent, 17-6 19-20 



Proportions. — Owing to the frequency with which the Macruri lose some 

 portion of their caudal extremities, the total length of a specimen, as it comes to 

 hand, is not always a safe unit to use in the computation of proportions, and it 

 happens that example A is certainly short of its natural length by several 

 centimetres. As appears to be usual, fin-rays, presumably from the anal fin, 

 have made their appearance on the mutilated end, simulating a caudal fin, much 

 in the manner illustrated by Giinther ("ChalL," vol. xxii., pi. xxx., fig. 2a) in 

 the case of M. serrulatus. 



The distance between the snout and the vent may also be distrusted, owing, 

 as we have seen when dealing with M. cequalis, to an irregularity in the position 

 of the vent which manifests itself in several species of Macriu'us. But when, as 

 in the case before us, the relations of the vent to the commencement of the anal 

 fin are about the same, the pre-anal length may be considered of some importance. 



TEANS. EOT. DUB. SOC, N.S. VOL. V., PAEI IX. 3 T 



