Class IV. SHAD HERRING. 463 



Gloucester in those months only, but none of 

 the emaciated shad are ever caught in their 

 return. 



The Thames shad does not frequent that river 

 till the latter end of Mai/ or beginning of June, 

 and is esteemed a very insipid coarse fish. The 

 Severn shad is sometimes caught in the Thames, 

 though rarely, and called Allis (no doubt Alose, 

 the French name) by the fishermen, in that river. 

 About the same time, and rather earlier, the 

 variety called near Gloucester the Twaite, makes 

 its appearance, and is taken in great numbers 

 in the Severn, and is held in as great disrepute 

 as the shad of the Thames. The differences be- 

 tween each variety are as follow : f 



The true Shad weighs sometimes eight 

 pounds, but its general size is from four to 

 five. 



The Twaite, on the contrary, weighs from 

 half a pound to two pounds, which it never 

 exceeds. 



The Twaite differs from a small shad only in 

 having one or more round black spots on the 

 sides ; if only one, it is always near the gill, 



* Belon also observes, that none are taken in their return, on 

 les prenri en rnontant contre les rivieres, et jamais en descendant. 



f I suspect that the Shad and Twaite are distinct species, and 

 correspond with the Alose and Feinte of Duhamel. Ed. 



