292 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



in '08, though almost identical in position with '07 

 (fig. 8). There has been in '09 no evidence of a really 

 great swarm in July or August such as we have 

 occasionally seen in former years ; but a chance observa- 

 tion made in July shows how easy it is to miss such an 

 occurrence. The official gatherings taken on July 15th 

 and 21st give no evidence of any unusual numbers, but 



F«v>. ' Mcr " A^w " M.qu ' cUe ' <Jv 



Uu. ' Am ' Se^c ' Oct ' Nc 



Fig. 8. Curves for Calanus in '07, '08 and '09. The clotted line 

 shows the average for the three years. 



ordinary tow-net gatherings, taken by Mr. Gravely and 

 Mr. Dakin for class purposes on July 17th and 19th, 

 yielded enormous hauls of Calanus, only portions of which 

 were preserved, but which it is estimated must have 

 reached at least 20,000 per net. 



We show here (fig. 9) what we take to be the ovum, 

 or rather the unhatched nauplius (measuring 0*68 mm. in 

 diameter) of Calanus hclgolandicus. That species has 



