758 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. [4] 



They appear in many cases to be surface swimmers. I have myself 

 seen schools of several thousands of Daphniadce of a greenish yellow 

 t;olor in the ditches south of Camden, N. J., swimming at the surface of 

 the water at midday in the bright sunlight. In the vicinity of Wood- 

 bury, in the same State, my friend Mr. W. P. Seal has taken great 

 numbers of abright-red colored Oopepod, apparently related to the genus 

 Pontella, and perhaps undescribed. They were sufficiently abundant 

 ill some cases to impart a red tinge to the water. 



Brady (Monograph British Coijepoda) observes in his introduction, 

 vol. i, page 9 : " The beds of fresh-water lakes seem to be very sparsely 

 populated with Oopepoda, and as to swimming species it may, as a 

 general rule, be said that the weedier the pool and the smaller its ex- 

 lent the more abundant in all probability the Entomostraca. , 



'' Many of the marine species pass their life apparently near the sur- 

 face of the open sea, and some of these, such as Calamis Jinmarchianus, 

 Gunner, and Anomolocera Patersonii, Templeton, are frequently found 

 in immense prolusion, the first-named species having been said to form 

 a xery important part of the food of the Greenland whale, and it is re- 

 markable that in the Arctic seas not only do the Entomostraca attain 

 an enormous development in point of numbers, but also in individual 

 size, Arctic specimens, for example, of Calanus finmarcManus and Me- 

 tridia armata being many times the bulk of those taken in our own lati- 

 tude." {I e.) 



According to H. Woodward, in his article Crustacea, Encyclopsedia 

 Britannica, the fecundity of the Copepoda is truly surprising. " Cyclops 

 quadricornis is often found with thirty or forty eggs on each side, and 

 though those species which have but a single ovisac do not carry so 

 many, their number is still very considerable. Jurine isolated speci- 

 mens of Cyclops, and found them to lay eight or ten times within three 

 months, each time about forty eggs. At the end of a year one female 

 would have produced 4,442,180,120 young ! Cetochilus is so abundant 

 both in the northern seas and in the South Atlantic as to serve for 

 food to such an immense animal as the whale. They color the sea for 

 many miles in extent, and when the experienced whaler sees this ruddy 

 hue upon the ocean he knows he has arrived at the 'pasture of the 

 whales.' They are to be seen in vast quantities off the Isle of May, in 

 the Firth of Fo) th, during the summer months. Many Cetacea, are at- 

 tracted thither, and vast shoals of fish also come to feed upon them. 

 One anomalous type of free Oopepod is the Notodelphys ascidicola, de- 

 scribed by Allman, which is found swimming freely in the branchial 

 sack of Ascidia communis.'''' 



The writer, in passing, would remark that he has frequently met with 

 Copepoda swimming freely in the ventral part of the branchial space 

 of Mya arenaria, in which the animals were i^robably not parasitical or 

 commensal, but had been drawn from without into the respiratory space 

 of the mollusk through the incurrent part of its siphon. 



