720 THE TETRAODONTOIDEA GILL. 



COLOMESIN.E. 



IL CoLOMESUS PSiTTACVS=Tetraodon 2)sittacus, Schn.^Batrachops psittacus BJh. 



CANTHIGASTERIDiE. 

 12. Canthigaster punctatissimus= Tetrodon punctatissimus Gthf. 



My knowledge of the cranial characters of Chonerhmns is derived 

 solely from the description and figures of Hollard. There is only one 

 specimen of C. naritus in alcohol in the National Museum. 



Any additional material will be welcoaied and equivalents given in 

 exchanges by the National Museum. 



The value of the skeleton, even for specifie distinctions, is well illus- 

 trated in the case of S. testudineus and 8. politus. Messrs. Jordan and 

 Edwards record the 8. politns as a "doubtful species," probably the 

 adult form of 8. testndineus* They also state that the old specimens of 

 T. politus "differ from 8. testudineus {annulatus) only, so far as we can 

 see, in the absence of prickles,"t and consequently "see little reason to 

 doubt that 8phero ides politus is simply the adult of 8. testudineus annu- 

 latus.^^ 



The National Museum has skeletons of 8. testudineus and 8. politus of 

 nearly the same length, and the differences between the crania of the 

 two is very marked, the former haviug the interorbital area compara- 

 tively narrow, and the prefrontal grooves narrow, while the latter has 

 the interorbital area very broad and the prefrontal grooves shallow 

 and wider \ 



* Proc. U. S. Nat. Mus., v. 9, p. 247. 



tProc. U. S. Nat. Mus., v. 9, p. 239. 



X Profs. Evermann and Barton have reached the same conclnsiou respecting S. poli- 

 tus and S. testudineus and have remarked that "the i7iterorbital space is flat" in S. 

 politus and "concave in 5. testudineus aniiulatus." (Proc. U. S. Nat. Mus., v. 14, p. 

 165, 1891.) No one, however, has noticed the difference in the width of the interor- 

 bital space. It will be interesting to compare the anatomy. of S. testudineus (typical) 

 and S. testudineus annulatus. 



