shut') hit — Robert Colleti on Pterycombus Inn ma Fries. 40 



The eighl leading ones which supporl rudimentary rays are all anterior 

 to the first neural -pine, and are in immediate contact with the supra- 

 occipital hone, forming with it, superiorly, a solid crest, the base-line of 

 which (23 mm.) is one-third less than the height. 



Those next succeeding possess the same breadth and length as the lead- 

 ing ones, and are quite as close together; but as we proceed backward, 

 the distance between them becomes slightly increased, and it is only after 

 we arrive at the posterior abdominal ones that they become decidedly 

 narrower and of a size less than the distance between any two of them. 

 In the caudal region they become progressively and rapidly reduced in 

 both the matter of length and size, until we reach the tenth and twelfth 

 caudals, where they are almost rudimentary in character. They exhibit 

 their greatest length (43 mm. ) over the anterior thoracic vertebrae, where 

 they are almost twice as long as the neural spines opposite them, with 

 the apices of which they come in contact. 



Interhsemal spines ("the ventral interspinal bones") are all slender 

 and rather short; they possess their greatest length beneath the anterior 

 caudal vertebra', but even here they are, for the series, shorter than the 

 corresponding haemal spines. 



The dorsal rays, 53 in number, in the specimen before me, start at 

 onceover the leading interspinals; the first eight, whose corresponding 

 interspinals surmount the superior aspect of the skull and precede the 

 first neural spine, are short. 



There are 41 anal rays. 



The Pseudobranchise, with a length of Hi mm. are well developed. 



The (Jills: The leading arch is supplied with a mesial row of "teeth," 

 eight in number, and about 6 mm. in length; they extend from a point 

 almost directly beneath the orbits, and are continued forward as mere 

 tubercles to the apex of the arch. 



The lower or inferior pharangeals likewise support (5) minute tuber- 

 cles. Upon the remaining branchial arches we find no true "teeth," 

 but only rudimentary tubercles in place of them. 



Tin: Literature of Pterycombus Bra ma. 

 (Translated.) 



1. Fries, B. Fr. Pterycombus brama, a new species of fish from the 



Arctic Ocean. (Kgl. Vet. Akad. llandl. 1837, pp. 14-22, PI. II. 

 Stockholm, 1838.) 



2. Nilsson, 8. Pterycombvs brama, Fries. Scandinavian Fauna, Part 



IV. Fishes, pp. 124-128, Lund, 1855. 



:'.. Liixjeborg, Wilhelm. Contribution to the knowledge of Pterycom- 

 bus brama B. Fries, a species of the Mackrel family. (Invitation 

 to the Upsala University Reunion, Nov. 4th, 1868, p. 0. Upsala, 

 L864.) 



4. Esmark, L. Contribution to the Fish Fauna of Finmarken. (Pro- 

 ceedings: Tenth Convention of Scandinavian Naturalists, Christi- 

 ania. lscs, p. 522. ) Christiania, 1869. 



