570 TELEOSTEI CHAP. 
or slightly anterior to the anal. The skeleton of Alepocephalus' 
is remarkable for its feeble ossification. Epipleurals and epi- 
neurals are present, and the bilateral division of the neural arch 
remains perfectly distinct throughout the praecaudal region, both 
halves being very loosely apposed. The air-bladder is absent. 
Ventrals are absent in Platytroctes, and the snout is much pro- 
duced in Aulostomatomorpha. 
Eleven genera are distinguished:—A, with scales: Alepo- 
cephalus, Conocara, Bathytroctes, Leptochilichthys, Narcetes, Platy- 
troctes, Aulostomatomorpha. B, without scales:—Xenodermichthys, 
Aleposomus, Leptoderma, Anomalopterus. 
Represented by about 35 species in nearly all the seas; as 
usual with deep-sea forms, individuals of the same species have 
been obtained from stations very remote from one another. 
Fam. 19. Stomiatidae.—I would unite under this name the 
Stomiatidae and Sternoptychidae of Giinther, an assemblage of 
aberrant deep-sea Fishes which agree in having the maxillary 
bone more developed than the praemaxillary, and beset with 
teeth, a character which differentiates them at once from all 
Fic. 345.—Malacosteus indicus. (After Giinther. ) 
other deep-sea forms of this sub-order, as well as from the 
Scopelidae among the Haplomi. The ventral fins are usually 
inserted very far back, and the number of their rays varies from 
5 to 8. Contrary to what occurs in other groups of fishes, the 
pectoral fins have a tendency to reduction, and actually disappear 
in some genera, whilst the ventrals remain well developed ; when- 
ever the pectoral fins are fully developed, as in Mawrolicus, 
Chauliodus, Astronesthes, and Photichthys, the mesocoracoid arch 
is present.” The form of the body varies exceedingly, even within 
the smaller groups into which this family has been divided; it 
may be excessively short and compressed, or excessively elongate, 
' A detailed description of the skull of Alepocephalus rostratus has been given by 
Gegenbaur, Morphol. Jahrb. iv. Suppl. 1878, p. 1. 
* As pointed out by Gegenbaur. These forms are, however, placed by Gill in 
a division characterised by the atrophy or absence of the mesocoracoid, 
