174 FAMILIES OF STNENTOGXATHOUS FISHES— GILL. vol. xviii. 



possession of tliat element to be one of the two cardinal characters 

 distinctive of the family Belonidiie.' 



It is not iu Belone alone, however, that the supplementary bone in 

 question occurs. It is also to be found (but in diminished proportions) 

 in the other Synentognaths. It was found quite independently by a 

 disciple of Dr. Jordan. In a letter to me dated April 21, 1894, Dr. 

 Jordan wrote: 



According to Mr. Stark, one of my students who is working out their skeletons, 

 there is a rudiment of this so-called coronoid iu all the Synentognaths as well as 

 iu Esox l^ Belone}. 



Dr. Jordan has aptly called the element in question the "so-called 

 coronoid".^ It can not be called appropriately the coronoid, as that term 

 implies homology with the bone so called in Lepidosteids, and between 

 those fishes and the Belonids is an impassable gap and a host of inter- 

 vening forms without any corresponding bone. The bone in question, 

 therefore, must have been independently developed, and consequently 

 shovtld receive a distinctive name. Addentary may be taken as a some- 

 what descriptive designatioj 



X. 



In the present communication, I have preferred to adhere to my pre- 

 vious estimate of the Exoc(f tines, Scomberesociues, and Hemirhani- 

 phines, and have retained them as subfamilies. Dr. Jordan, however, 

 has elevated them to family rank, and in a letter to me expressed the 

 following sentiments : 



I am inclined to think that the flying-fishes and the half-beaks at least should 

 be separated into distinct families, as the upper pharyngeals are fully united in the 

 latter and separated in the flying-fishes and iu ScomI>eresor. I am sure that difi'erences 

 of this grade would be accepted as family differences in large groups like the per- 

 coid fishes, and I do not see why they may not properly be so regarded here. There 

 is, however, no doubt of the close union of these forms as compared with Esox 

 [lieJone]. 



Dr. Jordan's opinions are entitled to the utmost consideration, and 

 it is quite possible that I may be convinced hereafter of the propriety 

 of this enhanced valuation of the characteristics of the several groups 

 in question. At present, however, it appears to me that the differences 

 of the pharyngeals in certain groups recognized by both of us as nat- 

 ural families, are quite as great as those manifested in the forms still 

 retained in the fiimily of Exocoetids. Such are the Sciienids, the Poma- 

 centrids, and the Labrids. 



'I have been unable to learn, either through an examination of Professor Cope's 

 works or through the author himself, where he had previously pointed out that 

 [^Bcloiie^ possesses a distinct coronoid bone. Professor Cope was unable to find anj' 

 previous notice. 



^The "coronoid" of ganoids can not be homogenetic with the homonymous bone 

 of reptiles, and, as the name appears to have been originally used iu connection with 

 the crocodile, the ganoid's may be called " coronine." 



