CATFISH GENUS NOTURUS RAFINESQUE 17 



have an additional posterior chamber to the air bladder; the latter 

 has a moderate backward extension of the patch of teeth on the 

 premaxilla. Their relationship to each other and to the genus Ictcdurus 

 should receive further study. Tentatively Istlarius balsanus Jordan 

 and Snyder is included in Ictalurus because of its resemblance to 

 that group and its probable affinity with Ictalurus jurcatus. 



The two syntypes (ANSP 22082-3) of Gronias mgrolahris Cope 

 (1864) were examined in the course of this study. They do not repre- 

 sent a distinct genus, but are specimens of Ictalurus nehulosus (Le- 

 Sueur) as maintained by Hubbs and Bailey (1947, p. 12). Fowler 

 (1915a, p. 208) regarded them as a distinct species of Ameiurus 

 [= Ictalurus]. Both have eight rays in each pelvic fin; the anal fins 

 have 19 and 20 rays; the pectoral spines are long and serrated posteri- 

 orly. Contrary to report the eyes are present, but are asymmetri- 

 cally developed — undoubtedly a teratological condition. 



The relationship of Trogloglanis pattersoni Eigenmann to the 

 Ictalurus group is suggested by several characters. In some respects 

 it resembles the species of Ictalurus which have high arched skulls, 

 a relatively shortened head, a long occipital process, and many gill 

 rakers (table 1). Also, like those species, the mouth is constricted 

 and inferior, but lacks teeth, the dorsal fin is slightly pointed, and 

 the lateral line is long. Otherwise, the presence of eight pelvic rays 

 (the specimen TU 10808 appears to have nine — perhaps an excep- 

 tion — rather than the eight reported) is certainly suggestive of re- 

 lationship with Ictalurus. The posterior flap on the anterior naris 

 is extreme but an elevation of the posterior rim of the naris is evident 

 in several Ictalurus, especially Ictalurus punctatus in which the con- 

 dition approaches Trogloglanis. 



Eigenmann (1919) thought Trogloglanis related to the genus 

 Schilbeodes [=Noturus] and Hubbs and Bailey (1947) regarded it 

 as more closely related to Ameiurus [= Ictalurus]. Although Troglo- 

 glanis has undoubtedly diverged considerably from its ancestral 

 ictalurid stock, it has few resemblances to Noturus or to Pylodictis, 

 and it is quite distinct from the other species of blind catfishes. 

 Eigenmann was undoubtedly impressed with the elongated adipose 

 fin (which was once thought to be unique to Noturus), but the more 

 recently discovered blind species also have a similar fin. Indeed, 

 the morphology of the specimens does not suggest derivation from 

 any of these stocks, or from the bullheads {Ameiurus auct) as postu- 

 lated by Hubbs and Bailey (1947). The few similarities to Ictalurus, 

 sensu strictu, which are listed above suggest derivation from a form 

 not greatly unlike /. punctatus. 



Noturus group. — Prietella phreatophila Carranza is similar in 

 many characters to the genus Noturus. Several features of the two 



