UNIVALVE MOLLUSKS 125 



Confounded with it. The Noble Doris, however, 

 grows to a much greater size, being sometimes as 

 much as six or eight inches in length. Its color is 

 a brighter yellow, and its tentacles are finger-shaped. 

 Internally, the differences are still more marked. 

 Abundant at Monterey. 



T'riopha car pent eri (Stearns), the Clown Sea- 

 slug. This little creature, seldom more than two 

 inches in length, is very common on brown kelp and 

 in tide-pools. The body is soft, almost transparent, 

 clearly showing the brown liver, and is of a white 

 color. On it are borne numerous processes which 

 are tinged with bright orange, and the mantle is also 

 spotted with the same color. When the animal is 

 extended the width is about a quarter of the length. 

 It is interesting to see the creature move in water. 

 Sometimes it comes to the surface and walks on the 

 air, as it were, head down. With its bright dress and 

 odd pranks it resembles a circus clown. 



T^riopha Diaculata^ MacFarland, the Blue-spotted 

 Sea-slug. This pretty sea-slug is about the size of 

 the last and is found in similar positions, though it 

 is not quite so common. Its color, however, is a deep 

 yellowish-brown, thickly set with small, bluish- 

 white, round or oval spots. It contrasts strongly 

 with the last species, which has a white background 

 and brightly colored spots. The foot of the Blue- 

 spotted Sea-slug is orange-yellow in color, and 

 touches of the same shade are seen on various organs 

 oi the body, especially the two club-shaped sense 

 organs, known as rhinophores, which stand out like 

 horns. 



