COPEIA 73 



viviparity to a high degree of perfection, the young 

 being born in an almost adult condition. Very little 

 has been written of their habits, and apparently 

 nothing at all of their copulation. So it was with 

 much satifsaction that I observed, under very favor- 

 able circumstances, the breeding habits of Cymato- 

 gaster aggregatus. The date of the observation was 

 July 5, 1916; the locality was in the shallow channel 

 forming the outlet and inlet of an estero near Goleta 

 in Santa Barbara County, California. 



Attention was first directed to a slight disturb- 

 ance about twenty feet offshore, where two "Shiners" 

 were swimming with their backs just out of the water. 

 Very soon the pair were joined by about 6 others, 

 which, judging from their small size, were likely 

 males. The original pair swam slowly towards shore, 

 their caudal regions in close proximity. The largest 

 of the supernumerary fishes immediately preceded 

 the pair, while the others followed a short distance 

 behind. Occasionally the male turned partly over 

 onto his side. After the fishes had proceeded thus 

 shoreward about 6 feet, there ensued a commotion, 

 of which the details were not observed, and then all 

 but the first pair swiftly made for deeper water off- 

 shore. 



The pair, now alone, then proceeded against the 

 tide in a semi-circular course of about five feet, fre- 

 quently pausing while the male, turning upon his 

 side, applied his anal region to that of his mate. 

 Finally reaching the shelter of a stone in about a foot 

 of water, the pair halted and copulation ensued. 

 With their heads in the same direction and their anal 

 regions in contact, the pair remained quite motion- 

 less for a few seconds, seeming to balance in the water. 

 The male then turned over to a nearly horizontal 

 position, the female much less. For several seconds 

 the male moved rather slowly about half an inch back 

 and forth, paused, then resumed the vibratory move- 



