SYNGNATHHXE SYNGNATHUS 



35 



dropping to the side at the thirty-third ring, while in the living forms 

 this occurs on the twenty-seventh. The type further differs from 

 S. CALIFORNIENSIS, in the greater depth of head, fewer dorsal rays and 

 rings, less extent of brood pouch and in the total number of rings. 



S. GRISEOLINEATUS Ayres, also common along the coast, has its 

 dorsal on 0+9 or ^ -\- 9 caudal rings instead of l /2-\-7 l /2, as in 

 S. AVUS. The latter deviates furthermore in having fewer dorsal rays 

 and shorter snout. S. BARBARA Swain differs from the type in having 

 its dorsal on -|- 8 rings. S. AULISCUS Swain has its dorsal on 1 + 8 

 rings, with fewer rays (29 to 33), fewer rings, and shorter head (in length 

 being 9.4 instead of 7). The Atlantic and Gulf Coast species of pipe- 

 fish have the dorsal farther forward on 4 -{- 5 rings, and head in length 9. 

 The common European species, S. ACUS L. is much like the species 

 from California. S. AVUS thus differs from each of the living forms 

 in essential points, standing unique in its stouter body, deeper head, 

 greater number of caudal fin rays, greater extent of the lateral line, 

 distinctness of ridges, coarseness of the gill-cover striae, larger eye, 

 angularly oval stellar platelets, the higher and shorter dorsal fin, and 

 the faintly latticed scales. 



The large number of vertebrae in S. AVUS suggests that it lived 

 in a cool sea, and a few fossil seaweeds imprinted in the chalky matrix 

 indicate habits similar to those of living species. 



TABULATED MEASUREMENTS IN HUNDREDTHS TO CAUDAL OF THREE 



SPECIMENS. 



