200 



covered with a network of hranchino- yellow cells. The 

 pectoral tins were distinctly visible at this stage (a day before 

 hatching). 



The newlv hatched larva proved to be well marked, being 

 readilv distingnished from all others on account of its large 

 size (4' I mm.) and uniform pale greenish yellow colouring, 

 which was absent onlv from the extremity of the tail. 

 Examined with a low power the colouring matter is found to 

 consist of bi-aiicliing black and yellow cells mixed indiscrimi- 

 nately. 



The position also of the heart is different from that in all 

 other larvae examined, being situated anteriorly in the 

 space in front of the yolk sac and immediately under the 

 posterior half of the eye. The notochord is multicolumnar. 



About three davs later a marked change was observed, the 

 colour had completelv disappeared from the median fins, and 

 the bodv became (^paque and of a dark green colour. The 

 posterior extremitv presented a bifurcate appearance 

 macroscopicallv, due to the absence of the pigment in this 

 region, and this mav be a useful diagnostic character. 

 Instead of swinuning about freely in the water like the other 

 larvae observed, this larva kept at the bottom of the 

 jar, head downwards, the tail keeping up a constant and 

 rapid vibration. 



[PrP.LISIIKD f.Tii jn.v, 1903.] 



