120 SELECTED NOTES FROM 



Spicules of Spongilla Fluviatillis (PI. XVI., Fig. i). — I have 

 had under observation a hving specimen of this sponge for the 

 last ten weeks, during which time it has grown, producing new 

 sarcode, in which also is rapidly forming new spicules, the form of 

 which is shown in plate, being bulged out in the middle. The 

 mature spicules are smooth and even, and pointed at the ends, 

 and slightly curved. 



Jas. Fullagar. 



Foot of Fly (PI. XVI., Figs. 2— 3).— In the foot of this fly, 

 which is very commonly found in corners of walls, etc., the pads 

 are unusually delicate and beautiful, the central one being 

 prolongated almost like a riband, I think there are not any 

 suctorial terminations to the hairs, that being entirely unnecessary, 

 owing to the flexibility of the pads themselves. 



E. TUTTE. 



Caligus (PI. XV., Fig. 3). — I wish to point out that the name 

 fish-louse, by which this animal is popularly known amongst fisher- 

 men, is not actually correct, though quite near enough in its 

 accuracy of definition to suit the purpose. It is a crustacean, 

 parasitic on many of our salt-water fish, and is itself subject to the 

 attack of a parasite, which lives upon or just under the edge of its 

 carapace. My observations of its life-history lead me to think 

 that its presence is not a certain indication (as has been asserted) 

 of disease in the fish upon which it is found ; for taking one large 

 family — the cod — it is rare to meet with one on which no single 

 specimen of this parasite can be seen. Yet it is ever found in 

 greater abundance on weakly and wasted individuals than on the 

 more robust and healthy members of the shoal. I remember two 

 years ago examining closely one morning over a hundred large 

 cod caught that morning at Newfoundland (a fishing ground just 

 oif the North Foreland), among which was one poor, flabby, 

 wasted fish, whose right eye had by some accident been torn out, 

 and was lying three parts out of its socket upon his cheek. The 

 injury was evidently of long standing, and the fish was poor 

 and out of condition, and overrun with the Caligus. I took 

 over forty of these parasites off it, and it was one of these which, 

 after being mounted by Mr. Topping, I sent round. The figure 

 in Baird's Entomostraca (Ray), so faithfully copied in our Note 

 Book, shows (at h) a second pair of jaws. These, however, I 

 have been unable to make out clearly in my own mounts or in the 

 vastly better mounts of Mr. Topping. 



W. Lane Sear. 



