GINGLYMACONCHA. SOLENID2. 259 
Hiatella arctica, Lam. Hist. Nat. des Anim. sans Vert. vi. 
partic. i. 30. 
Var. (3. Shell with its epidermis reddish. 
Inhabits the European seas amongst the roots of marine 
plants, or perforates marble. 
FAMILY III. SOLENID. 
ZQAHN, Aristotelis, Athenei, Dioscoridis. 
Solen, Plinii et Auctorum. 
The shells elongated, equivalve, gaping before and behind ; 
the umbones small, anterior terminal, at least placed before the 
middle; theligament external, hinge-shaped; the hinge toothed ; 
the epidermis thi. The respiratory tubes are either joined or 
coalescent ; the foot is either abruptly or gradually elevate. 
All the animals of this family inhabit the sea. 
Synopsis Generum. 
Testze longissimee, subcompresse ; cardine 
terminali; sinistro 2, dextro 1-dentato .. 9, SOLEN. 
Teste longissimee, rectze, subcylindricee ; 
cardine terminali, in utraque valva 1-den- 
PU a ee sce.) 2a. eee ea eek Oy. nem n Ee. 
Testee longze, compressze ; cardine subtermi- 
MME Ee eI eh 2 Pa ot) A Ph Pa 
Testee longze, compresse ; cardine paulo ante 
ATOM OCALOR: 20.400 315240) ol speeds S sexes! EZ.) ART USLUS. 
Genus 9. SOLEN. 
The shells very long and rather compressed; the hinge 
nearly terminal, anteriorly with two teeth in the left, one in 
the right. The tracheal tubes are equal and joined together, 
and ciliated at their extremities; the branchiz or gills very 
much elongated ; the foot gradually elevated ; its apex ob- 
liquely truncated. 
