Table of Contents
The mummichogs are small fishes made recognizable by having only one short soft-rayed dorsal fin situated far back, and ventrals situated on the abdomen, combined with a small mouth at the tip of the snout, a very thick caudal peduncle, and a rounded tail fin. The family is represented in the Gulf of Maine by three species, two of Fundulus and one of Cyprinodon, the former slender and the latter deep in outline, a difference in body form sufficient to distinguish the one genus from the other at a glance. The teeth are likewise different in the two genera, those of Fundulus being sharp-pointed, whereas they are wedge-shaped in Cyprinodon and incisorlike. The two local species of Fundulus are separable by their markings, majalis of all ages being barred or streaked with black while the adult heteroclitus is not.