of the Fishery Board for Scotland. 



129 



In luscus the ventral fin always extends past the anus, but in minutus 

 and esmarkii the tip of this fin often fails to reach the level of the anus. 



Of 18 examples of minutus, in 6 the tip of the ventral fin did not 

 reach the anus ; in 3 cases it reached the anus exactly ; and in 9 cases it 

 passed the anus. 



Fifty-two examples of esmarkii were examined for this character. In 

 20 the tip of the ventral fin did not reach the anus ; in 20 it reached the 

 anus; and in 12 specimens it reached past the anus. 



The tip of the pectoral fin extended past the anus in all the specimens 

 of each species in which the character was noted, viz., 9 examples 

 of luscus, 18 of minutus, and 43 of esmarkii. 



The Vertebrce. 



The details regarding the variation in the number of vertebrae in the 

 three species will be found in Tables L, II., III., IV. They are 

 summarised in Table VI. 



The average number of vertebrae was : — Luscus, 48*4 ; minutus, 49*4 ; 

 esmarkii, 53 "4. 



In the matter of the average number of vertebra?, luscus and minutus 

 come very near each other, the latter exceeding the former by one. 

 Esmarkii has the comparatively high average of 53*4. The higher 

 number of vertebras is accompanied in this species by a higher number 

 of rays in the unpaired fins. 



The average number of the vertebra bearing the first haemal arch was 

 16 in luscus, and the same in minutus, while in esmarkii the average, 

 was 18-6. 



The Urinary Bladder and Ureter. 



The urinary bladder in luscus has no lobe ; in minutus and esmarkii 

 it has usually two lobes. 



Luscus. — None of the specimens examined had a lobe to the urinary 

 bladder. The bladder in this form is coloured a silvery white. 



Minutus. — In the great majority of cases where this character was 

 noted, two lobes were found attached to the urinary bladder, one on each 

 side. This was the condition in 12 males and 39 females. In 6 speci- 

 mens (3 males and 3 females) one lobe only was made out. In no case 

 were both lobes absent. They are diverticula of the bladder, and vary in 

 size. Sometimes both are long, narrow processes ; one may be a short 

 flap ; or both may be small. 



In one female 23cm. in length the left lobe had a small secondary 

 lobe attached to it. 



In a female 25cm. long, captured in March, both lobes were large; 

 they were well supplied with blood-vessels, and their edges were frilled. 

 Two of the females got at the same time, measuring 23cm., had similar 

 lobes. In another March fish, a male 22cm. long, one lobe only was 

 found, and it was well supplied with blood-vessels. Another male, 

 22cm., captured in March, had two long lobes which were supplied with 

 blood-vessels, but were not frilled. A ripe female in June had large 

 frilled lobes. 



Esmarkii. — In this form there are usually two lobes to the urinary 

 bladder. In four cases, however, no lobe was made out. These fish had 

 been for two or three years in the preservative. In 15 specimens one 

 lobe only was distinguished, but in the remaining 63 examples in which 

 the character was noted both lobes were found. The lobes may be both 

 long, or one may be short, 

 i 



