42 Proceedings of the Biological Society of Washington. 



Breeding females showed the usual coloration of the species. 



In the male the anal papilla is small, bilobate, the sperm duct opening 

 at the tip of the papilla between the lobes, while in the female the open- 

 ing of the oviduct is much larger, and situated immediately in front of a 

 large, expanded, heart-shaped papilla, three times as large as that of the 

 male. 



SERRANID.E. 



46. Roccus lineatus (Bloch). Bass, striped bass, rockfish, rock. 



Common. Many ripe males were taken throughout April, but no ripe 

 females were seen. The males of this species mature when very small. 

 The following measurements were taken : 



1 ripe male 28 cm. long, weight % hb. 



1 ripe male 26.5 cm. long, weight % lb. 



1 ripe male 24 cm. long, weight ^ lb. 



1 ripe male 21.8 cm. long. 



One female with roe well developed, but quite hard, measured 96 cm. 

 in length and weighed 23 lbs. 



47. Morone americana (Gmelin). White perch. 



By far the most abundant resident species. The largest example seen 

 was 35 cm. long, and weighed 1J^ lbs. Individuals 26 to 28 cm. in 

 length, weighing 1 lb., were abundant. Small individuals, however, are 

 so exceedingly numerous that the average weight per fish, as taken in 

 the pound-nets, runs from .15 to .17 lbs. Examples of both sexes 12.5 

 to 17 cm. in length, averaging.il lbs. in weight, were found in spawning 

 condition. 



Eggs of this species were first received at the Battery Station on April 

 4th, and on the 8th of May the breeding season was by no means over, 

 a large proportion of the females still carrying unripe eggs. 



Pl.EURONECTID^E. 



48. Pseudopleuronectes americanus (Walbaum). Flounder. 



One example 32.5 cm. long, received from Eobin's Point, Maryland. 

 The water here is usually brackish. 



SOLEID.E. 



49. Achirus fasciatus Lacepede. Hog-choker. 

 Abundant. 



