APHEODITA. 243 



— a median and two lateral. The eyes are usually four in number and placed in pairs — 

 one in front of the other. 



As the result of their own researches they restored the older name Aphrodisiens for 

 Savigny's Halithees, and made three principal groups : (1) those in which the elytra 

 alternate with dorsal cirri and branchiae, (2) those having these organs on the same foot, 

 and (3) those devoid of elytra. In the first tribe the authors placed Aphrodita, Polynoe, 

 and Polyodonta. In the second division, which from the elongated body they termed 

 Aphrodisiens vermiformes, they ranged Acoete and Sigalion ; while in the third group is 

 placed Palmyre. We shall deal at present only with the first mentioned, viz. Aphrodita, 

 which was characterised by the authors as furnished with thirty elytra fixed to feet 

 which bear neither branchiae nor superior cirri, and which alternate regularly (with the 

 exception of the fourth and fifth segments) to the twenty-fifth segment, with other feet 

 which have cirri and branchiae. The elytra fixed to the succeeding segments are differ- 

 ently arranged. Three antennae are present. The jaws are small and cartilaginous or 

 absent. 



A sea-mouse and parts of its digestive system are figured in Tav. iv, fig. 10, of Delle 

 Chiaje's Memoire (1822), but no description is given. 



The same author 1 (1841) speaks of a pair of oval ovaries in Polyodontes maxillosa, 

 filled with a transparent liquid at the dissepiments and at the bases of the feet, and of an 

 analogous group of rosy ovaries in Hermione hystrix, and yellowish ovaries in A. aculeata. 

 These Meckel considered to be small branchiae. In April they had advanced consider- 

 ably. He did not consider the scales respiratory, as Cuvier, Carus, and Duvernoy had 

 done, and he supported his opinion by the presence of special branchiae in Sigalion 

 squamosum. He described the ventral ganglionic chain as a nerve-artery in A. aculeata 

 and H. hy stria, but had seen vascular trunks in both on the intestine. The blood-vessel 

 in his figure seems to ensheath the oesophageal trunks and ventral chain. Long before, 3 

 he had compared the alimentary system of the Aphroditaceans with that in such as 

 Pleurophyllidia. 



Oersted 3 (1843) signalised the Aphroditacea amongst the JSTematode-like Ohaetopods 

 as having imperfect branchiae (simple). He considered the scales the branchial organs. 



Grube's description of the Aphroditea in his ' Familien der Anneliden ' (1851) is 

 brief but characteristic. He included Palmyra under the same family. 



Sir J. Dalyell 4 says that, " though seemingly timid, the Aphrodita is probably fierce 

 and rapacious, overpowering creatures incapable of resistance ; and there is even reason 

 to believe that it occasionally devours its own kind." By Aphrodita he means the 

 Aphroditacea. 



Kinberg 5 (1857-8), following on the lines of Audouin and Milne Edwards, grouped 

 the Aphroditea of Savigny into seven families, the first of which, Aphroditacea, corre- 

 sponds with our Aphroditidae. These have an oblong wide body, with a rounded head 



1 ' Memoire/ vol. i, p. 121. 



2 1823. 



3 "Ann. Danie. Consp./ 1843, p. 4. 



4 ' Powers of the Creator/ vol. ii, p. 163, 1853. 



5 ' Eugenies Eesa/ &c, p. 1, 1857-8. 



