GENUS LAGENOKIIYNCHUS. 83 



7. LAGENOliHYNCHUiS Gniy. 



-^Lagenorhynchus, Gray, Zoology of thu Erebus autl Torror, 184G, p. ^^54. 

 <^Dvl])hinus of authors i^rior to 184G. 



^Elcctra, Gray, Suppl. Cat. Seals and Whales, 1871, p. 7G. 

 ^Leucopleunis, Gray, Suppl. Cat. Seals aud Whales, 1871, p. 78. 

 ^Lagenorhynchus, Gray, Suppl. Cat. Seals aud Whales, 1871, p. 70. 



Professor Flower, in his recent admirable review of the family Bel- 

 2)liini(la', gives tlie following diagnosis of the geuus LiKjcnorhynchas ; * 



Rostrum scarcely exceeding the length of the cranium; broad at the base and 

 gradually tapering toward the apex; depressed. Pterygoid bones normal, meeting 



in the middle line. Teeth small, not exceeding 4™'^' in diameter, "^ to f'r. Vertebrie 



very numerous, 80 to 90. Spinous and transverse processes of the lumbar vertebne 

 very long and slender; bodies short. Externally, head with a short but not very 

 distinct beak. 



In the coarse of my studies upon the genus I have found no cause to 

 take excei)tion to this diagnosis, except so far as the number of teeth 

 and vertebne are concerned. If the opinion i\xi\t t\xQ Lagenorliym-hus 

 tJticolea of Gray belongs to this genus is correct, the maximum number 

 of teeth must be set down as ^1, or ^|, instead of p. On another page I 



have shown that Lag enorhynchus obliquidens, Gill, has but 74 to 70 ver- 

 tebra'. 



In addition to the characters summed up by Professor Flower, I have 

 observed that the mandibular foramina in this genus are usually more 

 crowded together at the symphysis than in Prodelphinus and Delphinus, 

 and are not preceded by so deep canals. The presence of an area of 

 bright color rather high up on the side, between the dorsal fin aud the 

 flukes, likewise appears to be characteristic of the genus. 



The genus is, unquestionably, very closely allied to Frodelphiims. 

 The teeth are, on the rchole, more numerous, and the vertebra' less 

 numerous in the latter geuus, but some species oiProdelphinus have a less 

 number of teeth and a greater number of vertebrie than some specnes 

 of La/joiorhynchm, and vice versa. The proportional length of the beak, 

 the breadth and flatness of the interinaxillne, ai^pear to be the chief cra- 

 nial distinguishing characters which can be brought forward at present. 



The number of species which have been assigned to this genus is 

 quite large. In the following lists are included: (1) The species which 

 appear to me valid and as properly belonging in the genus, and their 

 synonyms; (2) species referred to the genus by previous writers, but 

 which I regard as belonging elsewiiere; (3) nominal species. 



1. Valid Species and their Synunyms. 



1. Lof/ciioi'ijiiichus acutus Graj. 1828. 



Syn. Delphinus eschrichiii Schlegel. 1841. 

 Delphinus I eucopleur us Ranch. 1843. 

 Lagcnorhynchtis prrfptcillatns Cope. 187G. 

 Lagenorhijnchiis giihernalor Cope. 1876. 



* Proe. Zool. Soc. London, 188:1, p. 511, 



