THE ANNALS 



MAGAZINE OF NATURAL HISTORY. 



" per litora spargitc museum, 



Naiades, et circilm vilreos considito foiites : 

 PoUice virgineo teneros li'ic carpite flores : 

 Floribus et pictum, diva', replete canistrum. 

 At vos, o Nympha; Craterides, ite sub undas j 

 Ite, recurvato variata corallia truiico 

 Vellite muscosis e rupibus, et mihi conchas 

 Ferte, Dea; pelagi, et pingui conchylia succo." 



PartkennZc\. 1. 



No. 95. JANUARY 1845. 



I. — On the Anatomy of Eolis, a genus of Mollmks of the order 

 Nudibrancliiata. By Albany Hancock and Dennis Em- 

 BLETON, j\I.D., F.R.C.S.E., Lecturer on Anatomy and Phy- 

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



[With five Plates.] 



1 IIE Nudibranchiate Moilusks are divided into two families, 

 the Doridce and the Tritoniada ; the anatomy of the former was 

 fully investigated by Cuvier, that of the latter, however, was only 

 partially examined by that illustrious physiologist ; and the Eo- 

 lidiria*, a very extensive division of it, were left totally unex- 

 plored, but were nevertheless considered to agree in organization 

 with Tritonia Homberyii, the tAqjical form of the group. 



Recently however tlie attention of zoologists has been drawn 

 to the subject by M. Milne Edwards, who was the first to point 

 out that the Eolidiim deviate in a very striking manner from the 

 rest of the family. He found in the genus CaUiopcea a ramified 

 digestive apparatus. This curious organ was supposed by that 

 gentleman to perform the double function of digestion and cir- 

 culation, and consequently to have analogy with the gastro-vas- 

 cular system of the Medusida on the one hand, and on the other 

 with the Xyniphun, on account of the ciecal prolongations of the 

 digestive organ that penetrate the exterior branchial papillje. 

 Since this discovery there has appeared in the ' Annales des 



* We use this name to designate the subfamilv of which Fa-Vs is the type. 

 /y- Ann. ^ Map. N. Hist. Vol. xv. ' B 



