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Part III. — Twenty-sixth Annual Report 



lake near Aberdeen, viz., Loch Loirston, little collections of bones. 

 They were uninjured, but the skull bones were disarticulated. They had 

 evidently been disgorged by some bird, probably a heron or a gull. They 

 were sometimes stuck together in a bolus, which indicated, no doubt, 

 that they had been disgorged a short time before. A similar bolus 

 consisting of the husks of grain was noticed also. 



The bones consist of the bones of the head, and one or two vertebrae. 

 The vertebral column is absent. 



One lot of bones consisted of those of merlangus. They were 

 accompanied by whole and crushed shells of Purpura lapillus ; the 

 latter were stained purple. The bones were readily diagnosed by the 

 otoliths, and by the fact that the following bones agreed with those of 

 a type specimen, viz., dentary, mandible, and premaxilla. 



The premaxilla was big in comparison with the other bones accompany- 

 ing it. It was distinctly a Gadid bone. It had two rows of tooth-sockets, 

 the outer very large, the inner very small. The latter tended to doubling 

 near the head of the bone. The sockets extended over the bone almost 

 to the tip. It was necessary to compare this bone with known premaxillae 

 of nearly the same size. It was compared in turn with the premaxillae 

 of callarias, pollachius, virens, aeglefinus, luscus, minutus, merlangus. It 

 agreed exactly with the latter. 



One difficulty arises from the fact that the number of rows of teeth 

 may vary with age. Thus in a pollachius measuring 36 cm. in length 

 there were three rows of teeth on the broader part of the premaxilla, 

 whereas as many as six rows could be made out on a big specimen, e.g., 

 85 cm. long. Again, a callarias measuring 23 '5 cm. had three or four 

 rows of small teeth on the premaxilla, next the head of the bone, while 

 an example 92 cm. long had six rows at least of small teeth in the 

 corresponding place. 



A second group of bones was found to consist of the bones of more 

 than one aeglefinus. The fishes were probably about 30 cm. in length. 

 The characteristic heavy clavicle, supra-clavicle, and post-temporal were 

 present. The premaxilla agreed with that bone taken from an aeglefinus. 

 The otoliths were present, but were not relied upon for diagnosis. 



The Rib (Pleur apophysis) in Pollachius. 



There are no ribs attached to the first and second vertebras. The third, 

 fourth, and fifth vertebrae bear stout ribs that have truncated ends. The 

 first of these ribs (fig. 44) is the heaviest, the others getting gradually 

 lighter. There are no transverse processes (parapophyses) on the third 

 and fourth vertebrae, and the head of the rib fits into a hollow in the side 

 of the centrum. The fifth vertebras has a little transverse process, and 

 as one proceeds along the vertebral column this process grows steadily 

 bigger. The rib is anteriorly attached to the under surface of the 

 parapophysis, but as the latter gets larger the rib is attached to the hind 

 edge of its extremity. The ribs of the sixth* and seventh vertebrae are 

 thinner and end in sharp points (vide fig. 45). Fig. 53 shows a rib 

 situated further back on the vertebral column, and fig. 46 shows the 

 shape of the head in different ribs. 



The epipleural spines are attached to the ribs towards the head of the 

 same. 



* In one case the rib of the sixth vertebrae had a truncated end. 



