68 EEPOET ON THE PENNATULIDA. 



which are thickenings on the edges of the lateral and under pairs of 

 mesenteries, and which, commencing at the lower end of the stomach, 

 only extend a short way down the polype cavity ; and two long mesen- 

 terial filaments, formed on the edges of the upper pair of mesenteries 

 (Figs. 5 and 7 s), and extending down quite to the bottom of the polype 

 cavity. All the mesenterial filaments are much convoluted, and the 

 two long ones are much thicker than in either of the other two genera. 



We have obtained evidence concerning the digestive function of 

 these mesenterial filaments of a precisely similar nature to that already 

 brought forward in the case of Pennatula ; i.e., we have found foreign 

 bodies, such as diatoms (Fig. 7, fo), imbedded in the filaments, and 

 clearly undergoing digestion. As these bodies become completely en- 

 veloped in and by the filaments, it is clear that these latter must have 

 the power of changing their shape and spreading round any body that 

 may come in contact with them, a power that is probably due to 

 amoeboid movements of the individual cells of the filaments. 



We described in Pennatula the presence of an Entomostracon, 

 apparently a parasitic Copepod in the body-cavity of one of the 

 polypes ; and we noticed also that ripe ova had been discharged from 

 the Entomostracon and were lying in various parts of the polype, some 

 freely and some imbedded in the mesenterial filaments ; also, that 

 many of these ova had commenced to develop. 



We have found ova precisely similar to these present in large 

 numbers in the polypes of Virgularia (Fig. 7, ov), and although we 

 have not found the Entomostracon itself, we have no doubt, from the 

 identical character of the eggs in the two cases, that those found in 

 Virgularia belong to the same animal as those found in Pe)inaiula,ov to 

 some very closely allied one. 



We have also found, what we were not aware of when writing our 

 account of Pennatula, that Entomostraca very closely similar to this 

 one have already been discovered in corresponding situations in allied 

 animals. 



In 1859 Bruzelius* described under the name of Lamlppe rubra a 

 parasitic crustacean which he found inhabiting specimens of Pennatula 

 rubra taken off the west coast of Sweden. Not long afterwards 

 Clapar^det found at Naples an allied form, which he called Lamippe 

 proteus, dwelling parasitically in specimens of Lobularia ( Alcyonium) 

 digitata, and wrote a careful account with figures of both the male and 

 female. 



Quite recently M. JolietJ has described and figured a third species 

 of tliis genus obtained from Paralcyonium elegans, and which he names 

 Lamippe Duthiersii. He notices, like Clapar^de, that the sexes are 

 distinct, and lays stress on the remarkable changes of shape which the 



* Bruzelius: " Uober einenin der Pe?i?iaf«to 7'(t&ra lebeuden Schmarotzer." 

 (Archiv. f. Naturgescli, 1859, bd. i., p. 2SG.) 



t Claparede: "Miscellanies Zoologiques," "Annalesdes Science Natiirelles," 

 " Cinquieuie Serie," tome viii., 1867, p. ii3 seq. 



* Lucien .Toliet : " Observations snr quelques Crustacc's da la Mediterrance," 

 '■ Arc'liives de Zoologie ex))eriin(nitnle ' tome x.. 1KS2. p. 101 seq. 



