Classification of tlie Order Lijomeri. 319 



skull in the latter is for the attachment of the enlarged 

 suspensorium, and is consequentlj more marked in Gastvo- 

 stoimis than in Saccopharynx. 



The vertebra3 of the Synodontida3 are also very similar to 

 those of the Lyomeri ; interiorly there are short processes at 

 the end of each centrum, exactly as shown in Zugmaycr's 

 figure of the anterior vertebrce of Gastrostomus ; the neural 

 arciies are slender processes, and in the vertebrse below tlie 

 dorsal fiu these are shortened and do not meet to form 

 unpaired neural spines. 



It is of interest to nolo that in the Apodes the pectoral 

 arch is pushed backwards by the large branchial apparatus, 

 but in the Lyomeri the pectoral arch and the reduced 

 branchial apparatus are displaced by the enormous pharynx, 

 the distensibility of which is increased by the pendent 

 movable etiimoid and the joint between the hyomandibular 

 and the quadrate. 



The order Lyomeri was first characterized by Gill and 

 Kyder (Proc. U.S. Nat. Mus. vi. 1883, p. 262), who gave 

 an account of the anatomy of Gastrostomus hairdii and 

 maintained the distinctness of these fishes from the Apodes. 

 Quite recently the anatomy of Gastrostomus has again been 

 described by Zugmayer (Rds. Camp. 8ci. Monaco, xxxv. 

 1911, p. 8S, pi. iv.). 



After comparison of the upper surface of the skull of 

 Saccopharynx with Gill and Kyder^'s description and Zug- 

 maycr's figure of Gastrostomus I agree with the former 

 authors that the Saccopharyngidaj and Eurypharyngidaj may 

 be regarded as distinct families. 



Family 1. Saccopliaryngidae. 



Mouth large; jaws with slender, curved, pointed teeth; 

 stomach very distensible; gill-openings much nearer to end 

 of snout than to vent ; skull longer than broad ; frontals 

 larger than the parietals. Piscivorous. 



A single species, Saccophary^ix ampidlaceus, Harwood, 1827. 



Family 2. Eurypharyngidae. 



Moulh enormous; jaws with minute teeth, the mandibles 

 sometimes with a pair of symphysial canines ; stomach not 

 specially distensible; gill-openings much nearer to vent than to 

 end of snout; skull not longer than broad; parietals larger than 

 frontals. Probably feeding mainly on small invertebrates. 



Eurypharynx, VaiU. 1882 (with symphysial mandibular 

 canines) ; Gastrosloinus, Gill and llyder, 1883 ; Macro- 

 pharynx, Brauer, 1902 (without pectoral fins). 



