Suborder Clupeoidea 



COMPOSITE AUTHORSHIPi 



Characters and Key to Families 



HENRY B. BIGELOW 



Museum of Comparative Zoology 

 Harvard University 



Characters. Eyes of the usual sort, i.e. not at the tips of short (tubular) cylinders 

 or of slender stalks, nor with orbital cavity extended downward. Adipose fin absent. 

 Pelvic fins at least no farther forward than midlength of body and farther rearward 

 than this in most, but lacking in a few. Fin rays jointed, and most of them branched. 

 Scales: the head naked, except in some Alepocephalidae; the trunk scaly in most, 

 but naked in some of the Alepocephalidae (p. 250); scales large, thin, their free bony 

 edge entire in most, often with crenulated membranous margin, but more or less 

 strongly pectinate in a few genera (Brevoonia, p. 342, Fig. 85; and Ethmidium); 

 exposed surface smooth or only weakly sculptured; midline of abdomen with scales 

 of the ordinary shape in most, but with a double row of larger, sharp-pointed, and 

 stiffer scales (scutes) in others (Clupeidae, pp. 257, 259, 260). Barbels absent on chin or 

 on throat. Luminescent organs lacking in most, but present in a few (some Alepoce- 

 phalidae and all Searsiidae). Lateral line well developed in most families (Engrau- 

 lidae, Alepocephalidae, Searsiidae) but not visible in others (Clupeidae) though 

 continuing rearward below scales to base of caudal except as it may occasionally 

 perforate a few anterior scales (jo: 957). Gill membranes wholly free from isthmus 

 in the great majority.^ Bony gular plate absent in chin region between branches of 



1. With the late Samuel F. Hildebrand contributing the family Engraulidae as well as the family Clupeidae, except 

 for the genera Harengula by Luis R. Rivas and Dorosoma by Robert R. Miller. 



2. Connected to the isthmus by a thin membrane in the anchovy Cetengraulis (p. 245). 



148 



