302 GASTEROPODES. 



5. EOLIS vmiDis. Plate XLIV. Figs. 11, 12. 



Length six lines; breadth under two. Tentacula and cornicula 

 nearly of equal length, rather cylindrical and obtuse. A black speck at 

 the base of each corniculum. Back bare ; bordered by ten pair of bran- 

 chial clusters of elongated papillae, three, four, or five papillae being in 

 each cluster. The central papillae of each cluster are the longest, the 

 exterior the shortest. They are always of a dark green colour ; the body 

 green, of various intensity. 



PLATE XLIV. 



FIG. 11. Eolis viridis, back, enlarged. 

 12. Belly. 



6. Eons SANGUIFER. Plate XLV. Figs. 7, 8. 



Length eight lines. Shoulder rounded ; lower extremity acute. 

 Head rounded in front, with two tentacula behind ; while, at some dis- 

 tance, are two smooth, long, and slender cornicula. These are so closely 

 approximated at the base, that they seem to fork from some lower or- 

 ganization. A black speck or eye behind each. Back bare, bordered by 

 two pair of branchial enlarging papillae. The branchiae do not evidently 

 form more than two clusters on each side in young examples. The whole 

 papillae of a large specimen amounted to forty-eight, being twenty- four of 

 a side. On one, half the size, the same number occurred, the four lowest 

 overtopping the extremity. No subdivision of these two clusters were 

 obvious, therefore the sides appeared to be clothed by only one. They 

 may, however, be rated at four in adults. Colour universally milk-white 

 or watery blue. The cornicula have a reddish tinge ; the branchiae 

 brighter than tile-red, their extremities white. The red is duller in 

 some specimens ; and it has faded with time in others. The young are 

 more beautiful than adults. 



This animal feeds on the Tubtdaria indivisa and on the Tubularia 

 polyceps, infesting those Zoophytes in numerous colonies. In the history 



