382 Mr. W. Clark on the Chemnitziae. 



and one of the great laboratories of the species-manufacturers, 

 who have turned them out with a liberal hand. This has in some 

 measure been occasioned by the singular variations exhibited by 

 the individuals of almost every species of the genus. 



Before I proceed, it may perhaps be desirable, for easy refer- 

 ence, at once to mention the principal essential generic cha- 

 I'acters of Chemnitzia, which, in my first memoir, 1 left to be col-' 

 lected from the numevous descriptions. 



Animal spiral, with a generally short but variably shaped 

 foot, labiated anteriorly, always furnished M'ith a suboval cor- 

 neous or SLibtestaceous operculum, of a character between that 

 of the Holustomala and Muricidce, that is, one of transition. The 

 tentacula ave short, tiiangular, sometimes with their edges folded 

 on the piiocipal stamens, conjunctive at their bases, forming in 

 many species a s.nall awJiing or veil, under which a long jjro- 

 boscidal muzzle ? is emitted, which i^juy be termed an involute 

 and evolute contractile proboscis ? The eyes are ionnersed at the 

 centre of the tentacular bases or at the internal angles, but have 

 never an exteiral position, though occasionally raised on minute 

 circular eminences. 



Mr. Alder tells us the head of Chemnitzia is veiy short, with- 

 out a muzzle, and that the mouth has no jaws, but is furnished 

 with a loiig retractile proboscis, as in the zoophagous gaste- 

 ropods. We will now see what M. Pbilippi says on this head, in 

 the ' Enum. MoU. Sicilife,' 2nd part, p. 136, sub fide D'Orbigny : 

 "Animal illi Eulimavum simillimum sed jn-oboscidiferum ; sic 

 describitur : buccje labiales coalitse, i7ifra tentacida exsertae, pro- 

 boscidem ahhreviatam, depressam, profunde emarginatam, sen 

 bilobam referentes." For comparison, I give an extract of what 

 M. Fhilippi says of Eulima : — " Caput ? vix in proboscidem pro- 

 ductum," 2nd vol. p. 134. Moll. Sicilise. 



Let us now examine M. Loven's characters of his genus Tur- 

 bonilla, our Chemnitzia : — " Proboscis sub basi vibraculorum re- 

 condenda, involvenda ; evoluta cervicem latitudine vix cedens/' 

 Whether these characters support those of M. Philippi, depends 

 on how the above terms are to be construed ; they are peculiar, 

 and accompanied by incidents not alluded to in any other of 

 M. Loven's true proboscidal animals, with respect to which, he 

 simply, in every instance, uses the words " proboscis recondenda," 

 which undovibtedly signifies a strict retractile proboscis ; but in 

 reference to the genus Turhonilla he qualifies that term and says, 

 it is rolled on itself and concealed under the bases of the tentacula, 

 and when unrolled it scarcely yields to the neck in width. The last 

 observation is very important, because if tlie proboscis is a re- 

 tractile one, it would be physically impossible to satisfy M. Lo- 

 ven's phrase. If this is the true construction of his characters. 



