418 SPH^ROMID.E. 



moderately produced at the inner angle. The maxillfe 

 are very delicate and thin membranous plates, setose at 

 the tip. (In our figures of the second maxillae in 

 D. rubra and Montagui, only one of the lobes was ob- 

 served on dissection.) The legs are moderately robust, 

 terminated by a strong hook, having a small tooth on its 

 inner edge. The tail is terminated by a simple slit, not 

 enclosing a central tooth, and the lateral appendages have 

 the outer lobe exposed. 



The species are of small size, and agree in their habits 

 with the Sphaeromae. They frequent rocky coasts, 

 preferring them on account of the small rock-pools 

 which abound in such situations, in which they reside. 

 They are also found among ThalasslophytcB at low water. 

 They swim with much quickness and elegance, turning 

 themselves over on their backs and executing various 

 evolutions with great agility. They are probably com- 

 mon all round our coasts. 



