2] 



frembæver, at hin har en forskjellig formel Mundaabning, 

 mere vinklede Vindinger og Ribbeme færre og mere fjer- 

 nede. Ved Sammenligninger af norske og amerikanske 

 Eksemplarer finder jeg ingen nævneværdig Difference i 

 Mundaabningens Fonn og hvad de ovrige Karakterer a.ngaar, 

 da er disse stærkt vexlende. Sum Regel er Ribbernes 

 Antal 14 — l(i. men jeg har Exemplarer for mig med indtil 

 2n. Farven er altid rød eller brunlig. Hos Bela nobilis 

 hav jeg gjort opmærksom paa, at der imellem Ribberne 

 er en dyb Indskjæring rundt den vinklede Del af Hoved- 

 vindingen og at den transverse Sculptur her viser sig uden 

 at være afbrudt af Kjolen. Hos B. harpularia er dette 

 ligeledes Tilfælde. Noget andet Slægtskab er der forøvrigt 

 ikke imellem disse to Arter. 



Hvad angaar det berettigede i specifik at adskille 

 nærværende Fonn fra Montagues B. turricula, da er jeg 

 ikke utilbøielig at tro, at vor nordlige Form kun er en 

 lokal Varietet og at det maaske vikle være korrektest at 

 opføre den som saadan under Montagues Art, 



Allerede Prof. Troschel 1 har gjort opmærksom paa 

 den fra de øvrige Belaer hoist afvigende Piltand hos B. 

 turricula og Sårs 2 paaviser en lignende Tand hos harpularia. 



Jeg har undersøgt en hel Del Exemplarer baade af 

 den hos os forekommende Form og af den sydligere, og 

 har i Tab. IX. Fig. 23 og 24 givet en Række Tegninger 

 af B. harpularia og i 25 a, b af B. turricula. Tænderne 

 er yderst tynde, bladformede og synes at veksle betydelig 

 i Form. Muligens er dette dog mere tilsyneladende ; thi 

 paa Grund af Tændernes Tyndhed vil det mindste Tryk 

 af Dækglasset have Indflydelse paa Formen og Tændernes 

 vexlende Stillinger giver ligeledes forskjellige Billeder. 

 Den Afvigelse, som der derfor viser sig imellem begge 

 Arters Tiender, kan ikke tillæggesj nogen Betydning i 

 specifik Retning. 



Udenfor N. Europa er Arten kjendt fra Grønland og 

 >«". Amerika, men derimod kan man ikke med Sikkerhed 

 notere den under Spitzbergens Fauna. Den norske Exped. 

 fandt den ikke der, men vistnok anfører Dr. Jeffreys den 

 derfra, dog maa den desuagtet staa tvivlsom. da denne For- 

 fatter slaar flere Arter sammen under sin Fleurotoma tur- 

 ricula. Prof. Leche angiver den ikke med tilstrækkelig 

 Tydelighed fra det Kariske Hav 3 . 



1 Gebiss d. Schnecken Bd. _'. Pag. 44, Tab. IV. Fig. 8. 

 - Moll. reg. are. Radula Tab. IX. Fig. 3. 

 3 Herzenstein (op. c. pag. I|VV ) angiver den derimod fra Mur- 

 manske Kysten. 



can species, and points out thai the former lias a differentl] 

 shaped aperture, more angular volutions aud fewer 

 ribs, placed also wider apart. On comparing Norwegian 

 and American specimens, I do not find anj noteworthy 

 difference in the form of the aperture, and as regards the 

 other characters, they are very variable. Usually, the ribs are 

 14 — 16 in number, but 1 have specimens before me with 

 as many as 20. The colour is always red, or brownish. 

 In Bela nobilis, T have pointed out that the interspaces 

 between the ribs, round the angulatad part of the Body 

 whorl, are concavely excavated and that, there, the trans- 

 verse sculpture appears without being interrupted by the 

 carina. In B. harpularia this is also the case. Any other 

 relationship, however, between these two species does 

 not exist. 



As regards the title to separate, specifically, the [ire- 

 sent form from Montagues B. turricula, I am not indis- 

 posed to believe that our Northern form is only a local 

 variety, and that it would he. perhaps, most correct to 

 retain it as belonging to Montague's species. 



Prof. Troschel 1 has pointed out the arrow-tooth in 

 B. turricula, which is so different from that of the other 

 Belas, and Sars- has shown a similar tooth in harpularia. 



I have examined a large number of specimens, both, 

 of the form occurring with us and of the Southern one, 

 and in Plate IX, figs. 23, 24 have given a series of illu- 

 strations of B. harpularia, and in Fig. 25 a, h of B. tur- 

 ricula. The teeth are extremely thin, laminate, and appear 

 to vary considerably in form. Possibly, however, that is 

 more apparent than real, because owing to the thinness of 

 the teeth, the least pressure of the cover-glass will have 

 an influence on the form, and different positions of the teeth 

 give, also, different impressions. The divergence which, 

 therefore, appears between the teeth of both species, cannot 

 be treated as of any importance in specific consideration. 



Beyond Northern Europe, the species is known from 

 Greenland and North America but, on the other hand, we 

 cannot state with certainty that it pertains to the fauna 

 of Spitzbergen. The Norwegian Expedition did not find 

 it there but it is the case that Dr. Jeffreys cites it from 

 that locality; it must nevertheless remain doubtful, as that 

 Writer includes several species in his Pleurotoma turricula. 

 Prof. Leche states, but not which sufficient distinctness, 

 that it pertains to the Kara sea 3 . 



1 Gebiss d. Schnecken Bd. 2, p. 44, PI. IV. fig. B. 



1 Moll. reg. arc Radula PI. IX, fig. :;. 



n Herzenstein (op. «•. p. fiS8) cites it. from the Murman coast. 



