GASTEROPODES. 307 



9. EOLIS MONOCEROS. Unicorn Eolis. Plate XLV. Fig. 1. 



I am induced to allude, in this imperfect paragraph, to a specimen 

 of the Eolis, with an organ which, from the preceding, may not be a 

 monstrosity. 



Length three lines ; body lanceolate, slender, with three scanty 

 clusters of long ellipsoidal papillse on each side of the back. A pillar 

 rises from the middle of the neck, which diverges into two cornicula, 

 with about seven whirls in each. The pillar and corniculum equal each 

 other's length ; and their joint length equals that of the tentacula. The 

 pillar is plain. It is situated between two black specks. Colour of the 

 body white ; centre of the papillae dark. 



This is a lively little animal, bristling up the papillae on any 

 annoyance. 



Only a single specimen has occurred, and a drawing made of the 

 corniculum. Before the whole subject could be executed, it had crawled 

 out of the water and perished. 



PLATE XLV. 



FIG. 1. Eolis monoceros Unicorn Eolis. Corniculum, enlarged. 



10. Eons TEXAX The Adhering Eolis. Plate XLV. Figs. 2, 3. 



Length seven lines ; body lanceolate, slender ; shoulders elongated, 

 in triangular processes. Tentacula and cornicula extending about two 

 lines. A black speck at the base of each of the former. Back rather 

 meagrely clothed with elongated branchial papilla;, not definitely ar- 

 ranged in clusters. Colour light watery blue. A white line traverses 

 the upper surface, also the back of the cornicula. and tentacula. Papillae 

 partly orange. The whole extremities tipped with white. 



A specimen occurred among the Tubularia polyceps, where it fed on 

 the epidermis of the zoophytes. It was small, and had few papillae. At 

 first the length of the cornicula and tentacula was equal to about a third 

 of the whole animal, which grew rapidly ; but they did not extend in 



