^66 



covered with a network of branchin,^ vellow cells. The 

 pectoral tins were distinctly visible at this stas^e (a dav before 

 hatching). 



The newly hatched larva proved to be well marked, being 

 readily distinguished from all others on account of its large 

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

 which was absent only from the extremity of the tail. 

 Examined with a low power the colouring matter is found to 

 consist of branching 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 days later a marked change was observed, the 

 colour had completely disappeared from the median hns, and 

 the body became opaque and of a dark green colour. The 

 posterior extremity presented a bifurcate appearance 

 macroscopically, due to the absence of the pigment in this 

 region, and this may be a useful diagnostic character. 

 Instead of swimming 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. 



[PUBLISHED 0th Jlly, 1903.] 



