290 NEOMENIA. 



" The Neomenise inhabit preferably rather deep water ; apparently 

 they generally live on muddy bottom. They differ widely as well 

 in habits as in station from the more elongated Neomeniens of the 

 Mediterranean, which live upon narrow fixed objects, Hydroids, 

 Gorgonians, roots of Alg?e, etc. 



" Koren and Danielssen who have observed Neomenia carinata (7) 

 in the living state, assert that, by throwing the margin of the mantle 

 to one side so that the foot becomes visible, it is able to creep up the 

 sides of the aquarium * like other mollusks ; ' indeed, that it is able 

 to swim on the surface of the water with the curved foot upward 

 and the back down. As has been already indicated, it may be 

 doubted whether the animal observed by Koren & Danielssen was 

 in reality Neomenia carinata. The facts cited above appear highly 

 improbable, and may prove to be erroneous. What is one to un- 

 derstand by the statement that Neomenia creeps with great rapidity 

 like other mollusks, considering that mollusks as a rule cannot 

 boast of great speed the snail's pace having always served as the 

 type of the slowest progress it appears improbable that Neomenia 

 should be distinguished by this characteristic Neomenia, in whose 

 so-called foot there is no muscular fiber and in whose body walls 

 but a weakly developed musculature, and which never possesses an 

 abdominal disk suitable for creeping. Moreover no other Neomenia 

 has been observed to move at other than an unusually slow pace. 



" I myself observed not many years ago a Neomenia carinata which 

 was kept for some days in a vessel of water. I observed no other 

 movements than an opening and closing of the- mantle opening, an 

 alternating extension and retraction of the proboscis, and a con- 

 traction of the body into an arched form with subsequent extension 

 so that it became almost entirely straight. During the entire time 

 the animal remained quietly in the same spot. 



" Prof. Tullberg similarly kept for some days living Neomenia 

 carinata in a vessel of water, and during this time observed no other 

 movement than the opening of the cloaca. 



"Prof. Theel, who observed during a longer period, a living indi- 

 vidual in an aquarium, the bottom of which was covered with sand, 

 informed me that the animal when undisturbed remained motionless, 

 buried in the sand in a vertical position, so that only the mouth of 

 the cloaca and gills were visible. If the animal was removed it 

 bored directly down again until the old position was reached. No 

 voluntary change of position was observed. From these observa- 



