332 66 



rudimenlary or quite absent; in latter case tail more or less prehensile. Ventrals 

 absent. Two nasal openings. No pyloric appendices. 



a. Subfamilj': Syngnathini. Preorbital bones 2; nuclial plaies generally 2 

 (one prenuchal and one nuchal); rarely 3 nuchals (one prenuchal and 

 2 nuclials). 



Genera: Siphonosioma, Syngnathiis, Ichihyocampus, Nannocampusj, Urocampus, 

 Doryichthys, Leptoichthysf, Coelonotusf, Stigmatophora', Nerophis, Protocampus f*. 



b. Subfamily: Hippocampini. Preorbital bones 3; nuchals 3 or 2; in latter 

 case prenuchal wanting. 



Genera: Hippocampus, Soleiiognutluis, Phyllopleryx, Gastrolokens, Acentronuraf. 

 -^. 3 nuchals, a prenuchal or "corona" being present. 

 Hippocampus, Solenognatlms. 

 -| — '\-. 2 nuchals, a prenuchal absent. 

 Gastrotokeus, Phyllopteryx. 



The genera marked with f I have not seen. 



That all the members of the group Solenichthyes are aberrant and much 

 specialised is evident, and that they must all be derived from one common stock 

 of less specialised forms is hardly to be doubted. But where their parentage is to 

 be sought, or to which of the other groups of existing Teleosts they are most 

 nearly related, is to me still an open question. As fossils, carrying quite the same 

 stamp as in modern time, they date far back in the tertiary formations; the existing 

 genera Amphisile, Aulostoma and Solenostomus as well as true Syngnathids {"Syngna- 

 thus bolcensis" Z\gn.) are found in Eocene (Ml. Bolca and Mt. Postale), Fistularia**' 

 at least in Oligocène formations (Glarus schists); unforUinateiy the extinct Eocene 

 genera Urosphen, Solenorhynchus and Calamostoma (Mt. Bolca and Mt. Postale), 

 which are undoubtedly Solenichthyes, the first belonging to the Aulostomidœ, the 



' 3 nuchals are present, a small prenuchal, a large first nuchal and a smaller second nuchal. Of 

 the two preorbitals the posterior (true preorbital) is very short, the anterior extremely long. 



■■ I have omitted the genus Osphyolax (with a single species: pelluciäus) described by Cope (Proc. 

 Ac. Sc. Philadelphia, 1875, p. 450, PI. 25; the description repeated in Jordan and Evermann 21a p. 775). 

 1 am quite sure tliat it is due to a mistake. Judging from tlie figures and description it must simply 

 be a Nerophis œqiwreiis, the dorsal fin of which has been damaged and deprived of its larger anterior 

 part. This would e.\pla)n not only the shortness of tlie dorsal fin, containing 16 rays in stead of 40—44, 

 but also the peculiar dorsal tube in front of the fin, whicli is said to be "closed above by a series of 

 small radiate ossicles in the median line, between which the cavity may be entered by small bodies." 

 These small ossicles evidently are the upper ends of interspinous bones with their peculiar osseous 

 expansions, which have been laid bare by the abrasion of the front part of the dorsal fin. The " free 

 superior edges (of lateral scutes), which form a series of longitudinal lateral grooves" in tlie "lumbar 

 region" I imagine are also due to accident !and drying'.'). 



*" "Fistularia teniiirostris" Ag. from Mt. Bolca cannot in my opinion be a true Fistularia; but it 

 belongs at all events to the Solenichtltyes, as also the genus Pseudosijngnattius (Syngnatlius opisthopterus 

 Ag.), which is no Syugnathid. 



