EASTMAN: FISHES FROM UPPER EOCENE OF MONTE BOLCA. 319 



the Aulorhynchidse and Aulostomidse, I am unable to appreciate any very distinctive 

 differences from the GasterosteidiE, and the clear affinity between Aulorhynchus 

 and Spinachia is such that I regard the family Aulorhynchidse simply as a conven- 

 ient one at the most, and as expressing the culmination in one direction of the 

 tendency characteristic of the order. I should be scarcely disinclined to dissent 

 from any one who should combine the Gasterosteidse and Aulorhynchidae in one 

 family." 



Starks' views on the same subject are thus stated: 



" Gasterosteus and closely related genera are the most generalized of the 

 Hemibranchs. They are the only ones in the group having the following typical 

 characters: Anterior vertebrse unmodified; suspensorium and mouth normal; ribs 

 typical; post-temporal approaching the normally forked condition, and parietals 

 present (the last a superfamily character). 



" Dr. Gill has pointed out how the tube-mouthed forms have descended in an 

 unbroken line from Gasterosteus through Spinachia and the family, Aulorhynchidse, 

 these constituting the superfamily Gasterostoidea. 



" The Gasterosteidse and Aulorhynchidse should perhaps be regarded as a single 

 family, but following the lead of the above authority, they are here kept separate, 

 though the latter family is regarded ' simply as a convenient one at the most ' " 

 (1. c, p. 622). 



Boulenger, in the Volume on Fishes in the Cambridge Natural History (1904), 

 subscribes to a similar opinion. He writes: 



" The genera Aulorhynchus and ^mKscms, each with one species from the North 

 Pacific, much resemble Spinachia in outward form and in the equal size of the an- 

 terior vertebrse, but the snout is still more produced, tubiform, and the ventral fins 

 are formed of one spine and four soft rays. The difference which justifies their 

 separation as a distinct family resides in the disposition of the ribs, which are flat- 

 tened and anchylosed to the lateral bony shields " (p. 631). 



According to the writer just quoted the extinct genus Protaulopsis, from the 

 Upper Eocene of Monte Bolca, does not properly belong to the group of sticklebacks, 

 as suggested by A. Smith Woodward, but should be associated with the Scom- 

 bresocidse. Another fossil genus, Protosyngnathus, from the fresh-water Tertiary 

 of Padang, Sumatra, is made by Boulenger the type of a new family, and regarded 

 as intermediate in position between sticklebacks and the Aulostomid division of 

 Solenichthyes. It agrees with the former group, writes this author, " in possessing 

 slender, free ribs, and with the latter in having the first vertebrse elongate, though 

 to a less degree than in Aulostoma." 



