ON DREDGING AMONG THE^'sil S r ?L^ND iSLlsS.^ ' 233 



having- been found in the Coralline arjd another i& the^Ee*el :Cija*.. J , Professor 

 Sars and Mr. M' Andrew dredged a few "sf>eciiienV off ^Ke^c6a:&t& -of ^Norway ; 

 and the former gave some interesting particulars of the animal, which I 

 have been able to confirm by my own observation. Although allied to P. 

 nivalis, and found in the same locality, it has distinct eyes placed on rather 

 prominent stalks or ommatophores, whereas P. nivalis has no eyes nor any 

 trace of eye-stalks. On this account Sars proposed the generic name Tt/phlo- 

 mangelia for the latter species ; but it must be borne in mind that Eulima 

 stenostoma is also eyeless, and yet is closely related to its congeners and com- 

 panions, all of which have very conspicuous eyes. It is a somewhat remark- 

 able coincidence that the shell of E. stenostoma resembles a large Achatina 

 adcula, which is in the same category as regards these so-called organs of 

 sight. The shells of P. carinata and P. nivalis are easily distinguishable. 



Among the rarer and more noteworthy mollusks procured this year were 

 the following : 



Montacuta tumidula, St. Magnus Bay and near Fetlar. Described by me 

 from the Hebrides in the Reports of the Association for 18.66. 



M. donacina, S. Wood. A single valve from deep water in St. Magnus 

 Bay. Another valve had been dredged by me at Falmouth in 1839. It is a 

 rare Coralline Crag fossil. Its nearest ally is M. substriata. 



Utriculus globosus, Loven. A small living specimen occurred this year 

 also in St. Magnus Bay. 



U. expansus, Jeffr. A few young specimens again in St. Magnus Bay. 



Odostomia Warreni, Thompson. Never having seen this shell in a fresh. 

 and perfect state, I considered it (Brit. Conch, iv. p. 143) a variety of 0. 

 obliqua. But the discovery of live specimens in St. Magnus Bay and near 

 Fetlar enables me to separate the two as distinct species. 0. Warreni has a 

 shorter spire and more swollen whorls than 0. obliqua, the suture is deeper, 

 the striaa are much stronger at the base of the shell, the whole surface is covered 

 with most delicate and close-set microscopic spiral lines, and the umbilicus 

 is well developed and deep. The animal of 0. Warreni has a peculiar foot ; 

 this is not plain and rounded at its extremity, as in 0. obliqua, but is deeply 

 bilobed or forked like the tail of a swallow. No other species of Odostomia, 

 so far as I am aware, has a similar foot. One individual spun a fine gluti- 

 nous thread from the middle of the foot, and kept itself suspended for some 

 time from the surface of the water, with the point of the shell downwards. I 

 found a dead specimen of 0. obliqua on the same ground with 0. Warreni. 



0. umbilicaris, Malm. A young specimen from St. Magnus Bay, nearly 

 globular, and thus exhibiting the same distinctive characters as the adult. 



Siphonodentalium Lofotense and Cadulus (or Loxoporus} subfusiformis were 

 again found, the former being more widely distributed. Both inhabit the 

 Mediterranean ; and the latter is a Sicilian and Viennese fossil. I had an 

 excellent opportunity of observing them alive and in active motion. The 

 thread-like and extensile organs by which the Solenoconchia seize their prey 

 are unlike the tentacles of any Gastropod, and their function is quite dif- 

 ferent. I would call these organs captacula, an appropriate word and not less 

 classically formed than tentacula. 



Leda pernula was dredged, as before, in St. Magnus Bay ; but with it was 

 a dead and apparently semifossil valve of Tellina calcaria. I must therefore 

 hesitate in considering the one more than the other recent or an inhabitant 

 of the British seas at the present time. 



Perhaps Lamellaria prodita, Lovcn, may be added to the list; but unfor- 

 tunately the specimen was handled too roughly, and the shell was crushed to 



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