31 



Arterne inden denne Slægt synes a1 være i høi Grad 

 polymorfe og «nu end denne smukke glatte Form er saa 

 hoist ulige alle de øvrige kjendte af Slægten, er jeg dop: 

 ikke sikker paa, at der vil vise sip Overgange til Solariélla 

 obscurus, Couth. De paa et Par Exemplarer af S. lævis 

 forekommende Spor af Spiralsculptur synes at antyde dette. 

 Typen for Solariélla, Wood er 8. mandata. Wood 1 og 

 denne er ifølge Jeffreys 3 Trochus cinctus, Philippi z= Machæ- 

 roplax amdbilis (Jeff.) Friele 3 = Machceroplax affinis (Jeff.) 

 Friele 3 . Hvis dette er correct, hvilket jeg ikke har havt 

 Anledning at forvisse mig om, saa maa Machærqplax vipe 

 Plads for Solar/ella, uagtet Wood selv senere i Crag Moll. 

 Pag. 135 inddrager Slægten under Margarita. Jeffreys 

 feiler imidlertid, naar han henfører Margarita cinerea, 

 Couth og Margarita groenlandica, Ohm. under Machæroplax. 1 



Margarita umbilicalis, Br. & Sowb. 



Tab. XI, Fig. 22, 23. 



M. umbilicalis, Brod. & Sowb. Zool. Journ. IV, Pg. 371. 

 Trochus umbilicalis, Phil. Conch. Cab. Martini & Chm. af 



Kuster, Pag. 245, Tab. 37, Fig. 2. 



Som Regel er M. umbilicalis mere rladtrykt end M. 

 groenlandica, Chm. Sculpturen er snart glat paa Oversiden 

 af Skallen, snart forsynet med nogle faa, ofte parvis op- 

 trædende Spiralstriæ og paa Undersiden tæt, fint spiral- 

 strieret. 



Størrelse: Mine største Exemplarer maaler 1U""" Axiall. 

 og 16""" Diam. 



Eadula viser ingen Afvigelse fra M. groenlandica. 



Forekomst: Den forekom talrig paa omkring 20 

 Favne Magdalenebay (Spitzbergen). 



Margarita striata, Br. & Sowb. 5 



Pl. XII, Fig. i. 



M. striata, Brod. & Sowb. Beechys Voy. Pag. 143, Pl. 34, 

 Fig. 11. 



1 Ann. & Mag. Vol. IX 1842, Pag. 531, Pl. 5, Fig. 7, 10. 

 - Mull. ..Lightning & Porcupine Exped." Part Yl 1883, Pg. 97. 



3 Tungebevælmg. hos de norske Rhipidoglosa 1876, Pag. 313. 



4 Jeffreys 1. c. Pag. 96. 



5 Hvis M. striata. Br. & Sowb. ikke kan beholde sit specitike 

 Navn, da der allerede er en Trochus striates, Lin. maa SI. polaris, Phil. 

 rykke op istedenfor, men jeg tror ikke, at denne Forandring er nød- 

 vendig, thi man resikerer neppe Misforstaaelse. 



The species included in this genus appear to be, in 

 a very great degree, polymorphous, and although this 

 beautiful, smooth, form is so verv unlike all the others of 

 the genus known, yet, I am mil certain that transitions 

 to Solariélla obscurus, Couth, will be traceable. The traces 

 of spiral sculpture appearing on a couple of specimens of 

 S. lævis would appear to indicate this. The type for Sola- 

 riélla, Wood, is S. maculata, Wood 1 aud that is according 

 to Jeffreys 2 Trochus cinctus, I'hilippi = Marine ropla.r amabilis 

 (Jeff.) Friele 3 — Machceroplax affinis (Jeff.) Friele 8 . If 

 that is the case, but of which I have had no opportunity 

 of satisfying myself, Machæroplax must give way for Sola- 

 ririla, although Wood himself, subsequently, in Crag Moll. 

 (p. 135), includes the genus under Margarita. Jeffreys 

 errs, however, when he assigns Margarita cinerea, Couth, 

 and Margarita groenlandica, Chm. to Machceroplax 4 : 



Margarita umbilicalis, Br. & Sowb. 



PL XI, tigs. 22, 23. 



M. umbilicalis, Brocl. & Sowb., Zool. Journ. IV, pag. 371. 

 Trochus umbilicalis, Phil.. Conch. Cab. Martini & Chm. by 



Kuster, pag. 245, PL XXXVII, fig. 2. 



As a rule, M. umbilicalis is more flattened than M. 

 groenlandica, Chm. The sculpture is sometimes smooth 

 on the upper surface of the shell, sometimes it is furnished 

 with only a few spiral stria- appearing, frequently, in pairs; 

 and on the lower surface it is compactly and minutely spir- 

 ally striated. 



Size. My largest specimen measures: Axial length, 

 10""", Diam. 16""". 



The Radula does not differ from that of M. groen- 

 landica. 



Habitat: It occurred abundantly in Magdalene Bay 

 (Spitzbergen); Depth, 20 fathoms. 



Margarita striata, Br. & Sowb.-' 



Pl. XII, flg. I. 



M. striata, Brod. & Sowb., Beechys Voy. pag. 143, PI. 

 XXXIV, fig. 11. 



1 Ann. & Mag. Vol. IX 1842, pag. 531, PI. V, fig. 7, 10. 



- Moll. „Lightning" & „Porcupine-' Exped. Part VI 1883, 

 pag. 97. 



3 Tungebevæbng. hos de Norske Rhipidoglosa 1876, pag. 313. 



4 Jeffreys Op. c. pag. 96. 



5 If 31. striata, Br. & Sow. can not retain its specific designa- 

 tion owing to there being a Trochus striatus, Lin. already, then M. 

 polaris, Phil, must be substituted, but I do not think this change is 

 necessary as there is scarcely room for misunderstanding. 



