882 CONTEIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY — IV. 



fork-tailed species, commonly referred to Amiurus, the two bones are 

 more or less close together; in some species apparently joined in the 

 yonng', bnt separated in the adnlt; in others apparently slightly sepa- 

 rated at the surface and joined under the skin. In but two species, 

 furcatns and punctatus, is there a continuous bridge formed at all ages. 

 In view of the complete intergradation of this character, we have re- 

 tained the name Amiurus for the species with truncate caudal and the 

 interspinal and su])raoccipital wholly separate, and Ictalurus for those 

 with forked caudal and the two bones in question joined or approxi- 

 mated. The only other alternative, and a not unreasonable one, is t(> 

 refer all these species to one genus, Ictalurus. 



On page 108, instead of Ictalurus lacustris, read: 

 106. 5. B«agrioa»»s (Le S.) Jor. 



The '^Gadus lacustrls^^* (Walb. Artedi, Pise. 1792, 144) can hardly 

 be identified with any fish. 



Page 110. To the description of Arius fells, the following may be 

 added : 



Bands of palatine teetb large, not prolonged backward over the 

 pterygoid region ; fontanelle prolonged backward in a narrow groove; 

 occipital process long, narrow, keeled. Pectoral rays I, 9. 



Arius equestris B. & G., is not distinct from A.felis, and should be 

 erased. 



Page 111. Instead of P lectospondyli read Order L. Eventognathi. 

 The latter name is unobjectionable, and has priority of date. 



Page 113. We do not believe that Ictiobus, Buhalichthys, and Carpi- 

 ixles can be maintained as distinct genera, and think it preferable to 

 unite the three under the earliest name, Ictiohus. In its dentition, 

 Ictiohus is intermediate between Carpiodcs and Buhalichthijs, and in 

 structure of mouth BiibaUchthys stands between the others. 



We have examined the original manuscript note-book of Eatinesque, 

 containing the descriptions which were afterwards printed in the Ich- 

 fliyologia Ohiensis. In this book is a drawing of his '■^Ictiohus hubalus,'' 



" It is described as follows: 



•'■Gadus lacustris, Americauis Mathemeg, Anglis Land Cod, Peunaut, Arct. Zool. 

 Introd. p. 191. Corpus tripedale, superue sul) spadiceum, infeme griseum; cirri tres 

 i)i maudibula inferiore, quorum medius longitudiuo duos alios vincit." 



The "Matbemeg or Laud Cod" of Pennaut is said by Richardson to be a cat-fish, 

 and it may have been /. nUjrlcans, but the description is wholly insufficient. 



