JUVENILE AND SEX CHARACTERS OF E. LYRICUS 
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young have teeth similar to that of the female but with entire edges. The lower jaw 
is also rather thin and somewhat pointed; and this together with the single row of 
minute movable teeth, suggests the mouth of a mullet. They have consequently 
been described under a separate genus, Mugilostoma. 
The conclusions stated above are based on a study of 86 males, 22 to 79 milli- 
meters in length, and 82 females, 30 to 68 millimeters, from the coasts of Louisiana 
and Texas. A total of 52 have been dissected, and the sex of the gonads deter- 
mined by teasing out a small portion and examining with a compound microscope, 
except in the case of females with well-developed eggs in their ovaries. It might 
be added that if one wishes to correlate the difference in the teeth with the sex and 
Figure 2. — Camera lucida drawing by Miss Louella E. Cable of the inner surface of one side of the lower jaw. A, female 
65.5 mm. B, male 60 mm. C, male 67 mm. D, male 69 mm. Note the striking difference, heretofore considered of 
generic importance, between A and D, and the gradual change in the male from B to D. In the upper jaw of the grown 
male the teeth are considerably larger than in the lower, and the change in the young male takes place much sooner. 
The smallest male figured already has the majority of the teeth in the upper jaw typically that of the grown male, and 
the contrast between the large raptorial teeth and the smaller bifid teeth quite striking 
the changes in the character of the teeth in the male, it is not necessary to examine 
the gonads microscopically since, like in many other gobies, the anal papilla forms an 
external character usable to separate the sexes readily. In the male the anal papilla 
is rather long, slender, and pointed, while in the female it forms a fleshy, bulbous 
tubercle and has a very deep fossa between it and the anal fin. This character 
readily separates the two sexes, except those of 27 millimeters or less when the 
difference is usually not marked. 
The collections from the Gulf coast have been used to work out the changes due 
to age and to sex. In order to fix definitely the status of the species and its distribu- 
tion and to include in the synonymy the various names under which it was previ- 
ously described from time to time, the following material has been studied. 
67308—31 2 
