514 PROCEEDINGS OF THE ACADEMY OF 



Another form was made known by Sir John Richardson under the name of 

 Notothenia, and placed by him in the family of Gobioids near Eleotris. From 

 that family, as naturally constituted, it decidedly differs by the caecal stomach, 

 the presence of pyloric appendages, &c. 



Dr. Giinther, in his Catalogue of Acanthopterygian Fishes, regarding the 

 lateral line as affording distinctive characters, distinguished two of his four 

 groups of the Trachinidoz by the continuation of that line to the caudal fin, or 

 its interruption or termination near the end of the dorsal fin. 



Eleginus having a continuous lateral line was referred to the Trachinina. 



Notothenia, with an inte r rupted lateral line, was placed among the ceseudo- 

 chromides. 



It. appears that the groups so characterized are only technical and artificial, 

 and not natural. The group Trachinina, which is arranged as the second of 

 the family, is composed of the following genera : Trachinus L., Percis Schneider, 

 Aphritis Cuv. et Val,, Sillago Cuv., Eleginus Cuv. et Val., Epicopus Giinther, 

 Percophis Cuv. et Val., Chcenichlhys Rich., Bovichthys Cuv. et Val., and Tricho- 

 don Steller. The genus Homalopomus of Girard, it is supposed, may also be- 

 loDg to the group. 



As regarded by us, there appear to be several distinct families confounded in 

 this one group. They may be briefly distinguished as follows : 



I. Lower pectoral rays simply articulated. 



A. Ventral fin thoracic. First and second dorsals sub- 



equal Trichodontoid^,. 



AA. Ventral 6ns jugular. 



Ventrals approximated. Anal very long. 



Body scaly TrachinojdjE. 



Ventrals separated by a wide area. Anal 



moderate. Body naked Bovichthyoid.*:. 



II. Lower pectoral rays branched. 



B. Head cavernous. Preoperculum abruptly bentinwards 



beneath the head. Ventrals thoracic Sillaginoid.*:. 



BB. Head with bones not cavernous. Ventrals jugular 

 or subjugular. 

 a. Snout not produced. Body scaly. 



b. Lateral line submedian along tail Latiloid^e.* 



bb. Fins trachinoid. Lateral line interrupted, or 



continuous on the tail Notothenioidje. 



aa. Snout spatuliform. Body naked ChjBNIChthyoid^;. 



The genus Homalopomus of Girard originated from a mistake of its author. 

 Its species is a member of the Gadoid genus Merlucius, near which it was sub- 

 sequently placed by its describer. A form that has been retained in the family 

 of Latiloidas, and which was first referred by Giinther to the Trachinina, has 

 nevertheless much resemblance to that genus. 



The characters used ic the above analytical synopsis, to distinguish the vari- 

 ous supposed families, are coincident with others of importance ; their com- 

 bination produces or accompanies special modifications of form and difference 

 of physiognomy, and those variations appear to be of family value. Such 

 families appear to be of equal rank with those accepted by the most scientific 

 of the modern therologists and ornithologists, and with those of the reptilian 

 orders of Chelonians and Saurians as viewed by Agassiz, Gray and others. 

 Their value also seems to be much greater than those of the families of Ophi- 

 dians established by Dr. Giinther, which have apparently very little title to 

 such rank;* it may be further remarked that some of the families recently 



* Mr. Cope, in his admirable series of memoirs on the Ophidians, is doing much to 

 equalize the groups of that order, and assimilate the value of its families, subfamilies and 

 genera to those of higher vertebrata. With many modifications, the families of Gun- 

 ther are more properly regarded as subfamilies. 



[Dec 



