100 Mr H. Goodsir 07i the Sexes of the Cirripcds^ ^c. 



In the beginning of March of the present year (1843), while 

 Professor Reid of St Andrews and myself were watching the 

 movements of some very large balani {Balanus TintinnahulmTi)^ 

 we observed a few of them ejecting with considerable force a 

 great quantity of small granules every time the cirri were re- 

 tracted. No great attention was paid to this at the time. 

 Next day, however, we were astonished to find the basin in 

 which the balani were confined swarming with an innumerable 

 number of extremely minute but very active animals, when it 

 immediately struck us that these must have been the young 

 which the balani were throwing off the day before. On placing 

 one of these animals under the microscope, we expected to find 

 one of these mussel-like animals described by Thompson ; but 

 instead of that, it had an almost exact resemblance to the 

 young of the genus Cyclops. To make sure that there had 

 been no mistake, one of the adult balani was opened, v/hen 

 the large cavity of the mantle was found to be filled with the 

 granules which we had formerly seen ejected. A few were placed 

 in a watch-glassful of sea- water under the microscope. They 

 were quite motionless, of an ovoid shape, sharper at one extre- 

 mity than the other (PI. IV., fig. 12). The eye, or rather what 

 was considered to be the eye, was observed a little before the 

 middle line, and near to the superior edge. In the course of a 

 short time, a few began to make some efforts to escape. After 

 they had done so, they were found to resemble, in their exter- 

 nal appearance, the young cyclopides alluded to above. At first, 

 the efforts to escape were feeble, but latterly they became 

 more violent ; and by means of the tail, which was suddenly 

 and forcibly jerked upwards and downwards, the membranes 

 which contained them were burst on the abdominal surface, 

 upon which the young animal escaped. It was some time, 

 however, before the extremities were completely freed. In 

 the course of ten or fifteen minutes after they had been taken 

 from the body of the mother, these young animals were all 

 free, and the empty sacs were lying amongst them. They 

 have a striking resemblance, in their external appearance, to 

 the larva? of the cyclops ; and if we had not had the certain 

 evidence of having seen them taken from the body of the 

 mother, we would have pronounced them young Cyclopides. 



After many fruitless endeavours, we found it impossible to 



