166 C. A. Westerlund, Synopsis Molluscorum Extramarinor. Scandin. 



Var. deshayesi Mich. (Compl. hist. moll. 1831): c. elongato- 

 ovata, marginibus subparallelis, ventrali subsinuato, pars 

 posterior altior, 2Y4 longior, in rostrum acuminato-trun- 

 catum, supra et infra seque subrecte angustata, modice 

 ventricosa, viride lutescens v. brunneo-olivaceolutea, cir- 

 cuitu obscurior, umbones pone marginem anteriorem, forte 

 decorticati, margarita albocoerulea, oleomaculata; long. 70 

 — 75 (Morch), long. 90, alt. 34, cr. 25 mm. (Loc). — Dania 

 in Tonderkanal et Tingslevso. — Eossm. Icon. f. 197. 



U. limosus Nilss. (Hist. moll. Sii. 1822). C. longa, fusca, antice 

 brevis, subtruncato-convexiuscula, depressa et angulata, 

 postice post medium usque plus minusve dilatata, delude 

 supra et infra sequaliter in rostrum late rotundatum vel 

 truncatum, stepissime crusta obtectum, Jonge producta, 

 margine ventr. recto v. curvatulo, postice brevissime ascen- 

 dente, carina ligamentali obsoleta; umbones lati, rotundati, 

 prominentes; callus marginalis altus, medio obtuse angu- 

 latus. 



Typus: c. in omnibus eetatibus saturate colorata, brunnea seu 



luteofusca, striis zoniformibus subrugosis saturatius fu- 



scis; long. 85, alt. 35, cr. 25 mm. — Eossm. Icon. f. 199. 



Forma maxima: rugpe incrementi confertissimae; long. 85 



—100, alt. 34-41, cr. 28—30 mm. 

 Forma pumila: long. 39. alt. 18 mm. 



Hab. Suecia in provinciis iisdem ac U. rostratus, sed ubi- 

 que rarior. — Dania in Sjaelland, Fyen et Jylland multis locis. 

 — Fennia ad Impilahti et Saaksmaki in Valkiakoski (Mus. Hel- 

 singf.). 



Gen. Wlargaritana Schum. 



C. crassa, iwnderosa, dente cardinali valvce dextrce 

 simplici, valvce sinistrce hipartito (vel dentibus diwbiis), 

 omnibus crassissimis^ conicis; denies later ales vel lamelli- 

 formes nidli. 



Ml. margaritifera Lin. (Syst. nat. X, 1758, Mya). C. ovali-oblonga, 

 compressiuscula, nigrobrunnea, margine dorsali arcum 

 circuli majoris formante, ventrali medio sinuato, unde 

 concha subreniformis; umbones depress!, soepissime decor- 



