458 Survey of Fishing- G^'ounds, West Coast of Ireland^ 1890-1891. 



By adopting it as the unit it becomes at once apparent that the head is relatively 

 longer, and the body relatively higher, in A than in B ; to express it more 

 exactly, the length of the head is in A about eight-tenths, in B seven-tenths, 

 and the greatest height of the body (situate in both examples as the anterior 

 ray of the first dorsal) is in A seven-tenths, and in B six-tenths of the length of 

 the fish in front of the vent. B is, in fact, judged by this standard, a more 

 elongate example than A ; but if we use the length of the head as the unit, we 

 find the height of the body relatively greatest in B. Such a condition is the 

 reverse of what might be expected from the analogy of other species (since B 

 is considerably the smaller of the two), and therefore tends to demonstrate the 

 importance of the pre-anal length in this particular case. The position of the 

 first dorsal, which is in A opposite to, and in B a little behind, the end of the 

 head, may also be taken as evidence to the same effect. 



Turning to the proportions of the head, we find the eye relatively largest in 

 B, viz. it is contained 4 times in the length of the head ; in A nearly 4|- times. 

 The relative dimensions of the snout and eye are also somewhat difierent, since 

 in B these structures are of equal length, whereas in A the former is slightly 

 the longer. Relatively to the height, the head is somewhat the wider in A. 

 The distance between the vent and the isthmus, a dimension which has been 

 found of use in the specific diagnosis of many Macruri, is naturally dependent 

 on the degree of elongation of the body, or on the developmental migration of 

 the vent, when such occurs. Accordingly in A the distance is not quite equal 

 to two-thirds of the length of the head, while in B it is more than four- fifths 

 of the same dimension. So far as proportions are concerned, the specimen 

 figured agrees very nearly with B. 



The net result of the comparison of dimensions appears to be that our 

 specimens show a greater and a lesser type of elongation, or a microcephalous 

 and a macrocephalous condition, of which the latter appears to be the more in 

 accordance with the normal condition (so far as that can be gathered from the 

 literature of the subject). The former type, however, is here associated with 

 what seems to be the more normal proportions of the head, inter se. 



Conformation. — In A the snout is comparatively blunt, and the anterior pi'ofile 

 only slightly oblique, as in the specimen shown in figure 2. The dorsal profile 

 rises in an unbroken curve to the commencement of the first dorsal fin. It is 

 smooth, and destitute of depressions, except immediately behind the snout, where 

 a moderate-sized sulcus occurs, as in figure 2, above the nostrils on either side. 

 The condition, in fact, bears a strong resemblance to that met with in figure 2, 

 the chief difference being that the inter-orbital space is slightly less convex in 

 the specimen figured. In B the anterior profile is much more oblique, forming 

 an angle of about 45°, with a vertical from the tip of the snout. The dorsal 



