Cockerell — Scales of Panama Fishes. 157 



phorus himamlatus Heckel, from Quirigua, Guatemala (W. P. 



Cockerell), but differ iu detail thus: 



Scales subquadrate, about 5 mm. long and broad ; apical circuli denser 



Xiphophorus . 



Scales broader than long, about 3.6 long and 4.5 broad; apical circuli 



not dense Pseudoxiphophorus. 



BELONID.E. 



Tylosurus scapularis scales look like very young scales of T. acus. The 

 structure is entirely the same. My material of scapularis is probably 

 immature. 



HEMIRHAMPHID.E. 



Hyporhamphus unifasciatus from Balboa, Canal Zone, differs from the 

 same species from Woods Hole, Mass., in the absence of the dense fine 

 circuli in the apical field, but it is immature. At the sides of the apical 

 field in the Balboa fish there are variable feebly developed circuli run- 

 ning upward instead of transversely, about two-thirds as far apart as 

 the uppermost ones of the basal field, which they almost meet. In the 

 narrow zone between these two sets of circuli are rudiments of the fine 

 transverse circuli which are so conspicuous in the Woods Hole fish. 

 The Balboa fish is presumably true H. unifasciatus ; that from Woods 

 Hole should perhaps be referred to H. roberti. It remains to be seen 

 whether fully mature scales from the Panama region will be readily 

 distinguishable from those of the northern fish. 



ATHERINID^. 



Atherina araea scales agree entirely in type with those of A. pinguis from 

 Australia, even to the frequent presence of a curious nuclear pit. 

 A. araea scales are however much smaller, about 1.5 mm. long and 3.5 

 broad. In Mem. Queenst. Mus., Dec, 1913, I have discussed the scales 

 of Atherina, and given an account of another Panama species, A. stipes. 

 The lobules in the middle of the basal margin of A. araea are usually 



two, but sometimes three. 



MULLID^. 



Upeneus maculatus scales do not differ appreciably from those of U. 

 dentatus. 



RYPTICID^. 



The scales of Rypticus are so entirely different from those of the 

 Serranidee that a distinct family appears to be indicated. The absence 

 of the anal spines, and other characters, further distinguish the group. 

 The group is called Grammistinte by Boulenger, and appears to include 

 three genera. Jordan and Evermann recognize two subfamilies, Gram- 

 mistinae and Rypticinae. 



Scales of Rypticus nigripinnis are minute, about 1.3 mm. long and .4 

 broad; greatly elongated, with rounded ends; nucleus central, elon- 

 gated; radii numerous, all around; circuli coarse; margin of course 

 wholly cycloid. Only a very small area is covered by skin. The apical 



