120 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



pleuro-visceral connective, which almost immediately passes into the 

 supra-intestinal ganglion ; in fact, the latter is only just separated by 

 a constriction from the right pleural ganglion. The former ganglion 

 gives off three nerves which supply the osphradium and gill and 

 complete the left half of the visceral loop, and also probably form 

 a dialyneurous connection with a nerve arising from the left pleural, 

 as in Volutilithes. The sub-intestinal ganglion (sb.g.) is intimately 

 related both to the left and to the right pleural ganglion, i.e. it 

 presents a zygoneurous condition ; it gives off two prominent nerves, 

 which run back, and one of them completes the visceral loop. 



The nervous system, on the whole, presents a highly specialized 

 condition, having attained almost a maximum amount of concentration, 

 far more so than that seen in Mclo Neptuni as described by Bouvier, 

 for in that form the supra-intestinal ganglion is separated by a wide 

 interval from the right pleural ganglion. The great development of 

 the pleuro-visceral connective in this species suggests a more primitive 

 condition than that met with in Voluta ancilla, unless it is possible for 

 the ganglia after once becoming concentrated to become secondarily 

 dissociated. 



2. Neptuneopsis Gilchristi, Sby. 



The external characters of this Prosobranch, a short account of 

 which has already been published, 1 are not at all suggestive of the 

 Volutidse ; for example, there is a very large functional operculum, an 

 uncommon feature in this family, being only met with in the genera 

 Voluiolyria and Lyria. The head also is unlike that of Foluta, since 

 it bears two very large massive tentacles (Fig. 2), the appearance 

 presented being that the head-lobes of Voluta had become incorporated 

 in the tentacles. There is a large snout, which in all probability 

 is introvertible, but this region of the specimen was considerably 

 damaged before I received it, so that it was impossible to determine 

 the point with any degree of certainty. The siphon is not so large as 

 in Voluta, and is devoid of appendices. 



The pallial complex, on the other hand, might be that of Voluta, the 

 form and relation of the organs composing it being in every respect 

 the same. 



The alimentary canal. — Unfortunately the buccal mass was removed 

 before I received the specimen, and in its removal the salivary glands 

 were practically destro3 T ed, one only of the tubular glands being left. 

 From general considerations 1 feel safe in concluding that these organs 

 would be precisely like those of Voluta. The rest of the alimentary 

 canal also might be that of V. ancilla (cf. Figs. 1 and 3), though 

 perhaps the oesophageal caecum is more largely developed in 

 Neptuneopsis. 



The heart, kidney, and genitalia ( 9 ) call for no comment ; like those 

 of Voluta they are typically rhachiglossate. 



1 Sowerby, op. cit. 



