46G On the Gadoid or Anacanthine Fishes. 



only in tlie more anterior ventrals, which have 1-9 rays, and 

 in having a separate caudal fin. Frontal bones united to 

 form an undivided plate (except in Merluccius), as in the 

 more specialized Macruridse. Vertebral column as in the 

 Macruridfe (except in Merluccius, in which ribs are absent 

 from the vertebrae with the strong expanded parapophyses). 

 Pectoral pterygials 4-5 in number. Scales small, cycloid. 

 Dorsal and anal fins often divided into two or three portions. 

 A mental barbel usually present. 



It has already been pointed out by Mr. Boulenger * that 

 the Gadidffi must be derived from fishes like the Macruridge 

 which have lost their caudal fin, as otherwise the structure of 

 the Gadid caudal, which is symmetrical, and supported by 

 the neural and hsemal spines of the posterior vertebrae, and 

 by basal bones similar to those supporting the preceding 

 dorsal and anal rays, is inexplicable. The Macruridaj, 

 although including many very aberrant types, are, in the two 

 essential characters of the more posterior ventrals and absent 

 caudal, less specialized than the Gadida?, which latter are 

 connected with the more generalized Macrurids through 

 Macria-onus. 



Genera: — Merluccius, Gadus, Halargyreus, Lotella, Phycisy 

 Phys'iculuSj Haloporphyrus, Lota, Molva, Onos, BregmdceroSy 

 Brosmius, Raniceps, &c. 



Family 3. Murseiiolepididge. 



Closely related to the Gadid^, from whicli they differ in 

 not having a separate caudal fin, in the gill-openings restricted 

 to below the base of the pectorals, in the increased number 

 (ten) of the pectoral pterygials f, and in tlie peculiar scales, 

 similar to those of the Anguillidse. Ventrals with 5 rays. 

 A mental barbel. Frontals forming an undivided plate. 



Genus : — Murcenolepis. 



* Ann._ & Mag. Nat. Hist. (7) x. 1902, p. 295 et seq. 



t The increased number of pectoral pterygials has been regarded by 

 Sagemehl (Morphol. Jabrb. x. 1885, p. 17) as indicating generalization, 

 and lias been a great stumbling-block in his discussion of the affinities of 

 Gymnotus with the other Ostariophysi, and especially the Characiuidte. 

 The fact, as Mr. Boulenger has pointed out to me, that the same feature 

 is repeated in three such distinct families as the Gymnotidas, Anguillidse, 

 and Murgenolepididae, and occurs in genera which are in all other respects 

 more specialized than their neighbours, goes far to prove that Sagemehl 

 was mistaken in his interpretation of this character. 



