Dr. R. Bergli on Phidiana lynceus. 135 



margin of the depression in which the tentacle stands, and 

 even further, so as to form a narrow black border along the 

 lobe between two succeeding tentacles ; in these cases the 

 underside of the base of the tentacle is occasionally also 

 coloured. In some individuals no pigment was observable, 

 and the tubercles were then generally but little developed. 

 These latter are of a firm consistency ; and their colour is due 

 to peculiar cells, which stand perpendicular on the surface, and 

 much resemble those observed in the eyes of various mollusca. 

 No ganglion could be found in the base of the tubercles ; and 

 therefore the tubercles in question cannot even be regarded 

 as merely photoscopic eyes, much less as corresponding in 

 structm-e with the real eye of these animals. Something 

 similar, but in smaller degree, was observed in M. cinereaj 

 Couth, (var. grandis). The real eye in Margarita was seen 

 as a black spot shining through the apex of the ophthalmo- 

 phorium ; and on this spot a small oval opening was observed, 

 of varying size, and which could be distended by pressure. 

 No lens, nor apparently any vitreous humour existed. A simi- 

 lar opening seems to exist on the eye of Fissurella rosea (Lam.). 

 If these observations are confirmed, the eye will in these 

 animals exhibit the same remarkable structure, without diop- 

 tric apparatus, which has been found in Nautilus. To return 

 to Phidiana lynceus^ it may be observed that a doubling of the 

 eye on one or both sides has certainly been observed as a mon- 

 strosity in many Gasteropoda ; but the occurrence of accessory 

 eyes in the Phidiana was certainly no monstrosity, for the 

 three individuals examined agreed perfectly in this respect. 

 Nor could these organs be interpreted in any other way than as 

 eyes. There exist, no doubt, ^olididse in which the ear remains 

 in its embryonal stage, with one otolith ; but, excepting a few 

 Pteropoda, there exists scarcely any Gasteropod in which the 

 ear exhibits such a development of pigment as is seen in the 

 organs referred to in Phidiana lynceus. 



The band or tube connecting the sacs which contain the 

 urticating cells with the lobes of the liver was unusually long 

 in this species, rolled up in a coil generally placed on one side 

 of the lobe. Both cysts and free urticating cells were seen 

 dispersed through the whole length of the tube. Dr. Bergh 

 does not agree with the theory advocated by Prof. Huxley, 

 Dr. Gosse, and Mr. Strethill Wright, that the urticating cells 

 in ^olididse are a kind of fsecal excretions, and derived from 

 the animals on which they live ; for sacs containing urtica- 

 ting cells are wanting in many genera, as Emhletonia^ Fiona^ 

 Phyllodesmiumj in Hermacinas and Proctonotinse, though these, 

 or at any rate most of them, certainly feed upon animals which 



