PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 61 



of Mitcbill and Harwood since 1871. These descriptions were read then, 

 with the volume of Dr. Giinther in view, and naturally- the description 

 of the modern author was regarded as counterbalancing those of the 

 older ones, although there was sufficient doubt in the mind of our senior 

 to cause him to regard it even then as a strange form of doubtful perti- 

 nence to Apodes. At first, in our recent communication, we were dis- 

 posed to collocate the family Saccopharyngidte in the order Lyomeri, but 

 Dr. Gilnther's positive statement respecting the "enormous .... head" 

 and his utter silence respecting the weighty characters signalized by 

 the older authors, tiually restrained us from so doing. On our return to 

 Washington, we availed ourselves of the opportunity to investigate the 

 literature of the subject, and not only read but studied the descriptions 

 of Mitchill, Harwood, and Johnson. These, which previously had little 

 significance or were regarded as perhaps erroneous, were then found to 

 be more valuable than was at first thought, and to be susceptible of 

 being j^erfectly understood in the light of our recent researches. We 

 cannot now doubt that the older authors were correct in most of the 

 characters that they assigned to the forms examined by them, and in- 

 deed the changes which the oral parts may undergo, and the allusions 

 made can only be understood when we concede that a fish of the Lyom- 

 erous type was under examination by them. Even the peculiar aspect 

 of the pectoral fins, as described by Harwood, which was not appre- 

 ciated by Johnson, is now capable of explanation, inasmuch as the scap- 

 ular arch is quite broad and has tumid muscles, which, by the contrac- 

 tion of the surrounding skin, would present the appearance of an adi- 

 pose disk, such as was noticed by Harwood. 



In 1883 also. Dr. Gill, in our joint behalf, communicated a letter to 

 ^Nature, in which he besought from English naturalists a re-examination 

 of the specimens of Saccopharynx claimed to be in the British Museum, 

 and gave the results of our studies up to that time in the following 

 terms : 



" The Lyomeri are fishes with five branchial arches (none modified 

 as branchiostegal or j^haryngeal) far behind the skull ; an imperfectly 

 ossified cranium, deficient especially in nasal and vomerine elements, 

 articulating with the first vertebra by a basi-occipital condyle alone ) 

 with only two cephalic arches, both freely movable, (1) an anterior 

 dentigerous one, the palatine,* and (L>) the suspensorial, consisting of 

 the hyomandibular and quadrate bones ; without opercular elements; 

 without maxillary bones, or distinct posterior bony elements to the 

 mandible,t with the scapular arch imperfect (limited to a single carti- 



* We liad at first adopted the homological identification of Owen and others for the 

 anterior upper dentigerous bones of the Lyomeri, but a study of the histology and in- 

 iitTvation of the bones and a consideration of the mode of development of the jj.ala- 

 tine bones in typical fislies compel us to regard them now as maxillary. 



t Indistinct bony elements have since been detected in the mandibular rami of a 

 larger specimen. 



