DORIS ASPERA. 



eastern coast of England, where it is found under stones near low-water mark ; sometimes 

 four or five under one stone. From its small size, it appears to have escaped the notice of 

 naturalists, or it may have been passed over as the young of B. pilosa. We have few records 

 of its capture on the western coasts, where its place seems to be taken by nearly allied 

 species. 



Doris aspera comes very near the B. muricata of Miiller, from which it differs principally 

 in its smaller size, rather smaller tubercles, and almost constant white colour. There is, 

 however, a group of species in this section of Boris so nearly resembling each other, that it 

 requires more detailed characters than those given by Miiller to discriminate them. D.fusca 

 of Fabricius (a white species), and B. acutiuscula of Moller, appear to be very nearly allied to 

 B. aspera. Our D. proxima is also very closely related. 



The Boris aspera of Macgillivray must be something different from ours, as he describes 

 it as having two small oral tentacles and the branchiae retractile. It was probably a very young 

 white variety of B. tuherculata. 



This is comparatively an active animal, more restless than most of its congeners. When 

 kept alive for observation, it frequently floats inverted at the surface of the water, and, like 

 most of the littoral Borides, it is apt to creep out of the water, and, if left over night, will often 

 be found dead and dried up in the morning on the side of the glass. 



It spawns in May, June, and July. The spawn is deposited in a narrow coil of two or 

 sometimes three volutions, and is from a quarter to four tenths of an inch in diameter. The 

 eggs are white, and rather thinly scattered through the gelatinous envelope without apparent 

 order. 



Figs. 1, 2, 3. Doris aspera, different views. 



4. A dorsal tentacle. 



5. A branchial plume. 



6. A portion of the cloak, much enlarged. 



7. Spicula. 



8. Spawn. 



9. A portion of the same, shewing the arrangement of the eggs. 



