Interim Account of 

 Family Alepocephalidae 



HENRY B. BIGELOW 



Museum of Comparative Zoology 

 Harvard University 



Characters. Essentially as in the Clupeidae, except with the Dorsal fin consider- 

 ably posterior to the midlength of body, its base partly or entirely over anal fin and 

 preceded in a few {Anomalopterus) by a fleshy fold or ridge. Lateral line present in 

 most (described as indistinct or lacking in Xenodermichthys, Leptoderma, and Anomal- 

 opterichthys). Swim bladder lacking. Color ranging between dark blue, purple, and 

 black, below as well as above; transparent but never silvery. Barbels lacking on chin 

 and throat. Bony gular plate absent in throat region. External tubular papilla 

 absent on shoulders (present in Searsiidae, p. 254). Abdomen rounded, its midline 

 without keeled scales (scutes). Snout less than twice the length of mouth in most, 

 not tubular, but tubular and more than twice the mouth in a few {Aulostomatophord). 

 Mouth ranging from very small, at tip of tubular snout (see above), to a little more 

 than half as long as head [Anomalopterus and Bathytroctes'). Pectoral fins very small; 

 rudimentary in a few (Mirognathus). Pelvic fins present, at least in most. Teeth small, 

 feeble, present on premaxillaries in most (upper jaw toothless in Anomalopterichthys, 

 Leptochilichthys, and Asquamiceps), and on maxillaries, palatines, and mandible in some. 

 Scales present or absent; if present, thin, rounded. Luminescent organs (photophores) 

 lacking in most but present in a few; situated on nodules of raised skin if present. 

 Vent posterior to midlength of trunk in most (anterior to midlength of trunk in Lep- 

 todermd). Gill membranes free from isthmus and overlapping. Opercular system 

 thin but complete. Gill rakers long, numerous. Branchiostegal rays 5 or more. 

 Pyloric caeca 2—21 reported (rudimentary in some). 



Genera. Parr, in his recent synopsis of the family, recognized 22 genera, six of 

 which were described by him as new (^: i — 14); to these he added two more new genera 

 a year later (5: 263, 265). 



250 



