88 Messrs. Hancock and Emblcton on the Anatomy of Eolis. 



pellucida? ; interiores petaloidese, tenerrimse. Stamina tria ; fila- 

 menta gracilia, antheris longiora ; antherse obovatse, compressse, 

 loculis granulis pollinis inter se conglomeratis repletis, dehiscentia 

 ignota. Stigmata tria, bipartita (?), cruribus recurvis perianthii 

 laciniis exterioribus duplo longioribus. 



Obs. Elodea canadensis (Michx.) a specie supra descripta differt, 

 ob verba auctoris in delineatione characters generici, *' ovarium ad 

 caulem sessile." Inde stirps ad Anacharidem canadensem (Planch.) 

 verosimiliter recte referta. 



EXPLANATION OF PLATE VIII. 

 Anacharis Alsinastrum, natural size, with a detached flower showing its 

 very long tube. 



Note. — The flower, the only one obtained, is doubtless imperfect, by 

 wanting the third stigma. 



a. A whorl of leaves. "1 



b. Summit of the sheath. „, .„ , 



c. A female flower. ^Magnified. 



d. Stigmatic fringe. J 



We are indebted to Mr. J. W. Salter for the beautiful drawing, 

 made for the ' Supplement to English Botany/ from which our 

 plate is engraved. 



IX. — On the Anatomy of Eolis, a genus of Mollusks of the order 

 Nudibranchiata. By Albany Hancock and Dennis Em- 

 bleton, M.D., F.R.C.S.E., Lecturer on Anatomy and Phy- 

 siology in the Newcastle-upon-Tyne School of Medicine. 



[Continued from vol. xv. p. 88.] 



[With two Plates.] 



Organs of Generation. 



For the sake of convenience we will treat of these in the fol- 

 lowing order : — 



1st. Male apparatus : testis and penis, and mechanism for 

 intromission and retraction. 



2nd. Female apparatus : ovary with oviduct and accessory 

 glands. 



3rd. Complementary androgynous organs : spermatheca and 

 its channels. 



The generative organs lie for the most part beneath all the 

 other viscera, and occupy the greatest part of the cavity of the 

 body. The ovary at the season of reproduction nearly fills up 

 the posterior half of the body, and the median line divides it 

 into two almost symmetrical parts. 



The other organs lie in front of the ovary, and extend as far 

 forwards as the sides of the buccal mass ; they are unsymmetrical, 



