Mactridae. — Myidae. 145 



(litus; branchiae binae utrinqiie inaequales; pes sulcatus; testa inaequivalvis, crassa, 

 postice hians. niargines epidermide crassa tecti ; cartilago foveae valvae sinistrae 

 insidens. 



Mya L. Mari/incs iiaUii tmifi , rinia pcdali excepta ; aiphones covjiincti epi- 

 derwide rtujosa tecti , pcrlonfii , non prorsus retracfiles, corova fcntaculorum munifa, 

 orificium anale valmila conica pracditum; palpi elongati; hranchiae non in siphoncm 

 hraiichialcm porrcctae; pcs parius linijuiformis, suJco hrevi, sed sine hysso ; testa oh- 

 loiiffa , suhiiiacquilatcra , postice hians ; cardo dextra dentc primario parvo, sinistra 

 dciifc Jafo friaiif/id". locJdcariformi. 



1. M. truncata L. Testa oblongo-ovata , fere acquilatera, sat convexa. 

 postice valde liians, epiderniide rugulosa, antice rotundata, postice abrupte verti- 

 caliter truncata, margine ventrali fere recto ; umbones subtumidi, incurvati, fere 

 mediani. — Long. 60 — 70 mm. 



Distrib. : Athmticura septemtrionale et boreale. — Fossilis in stratis 

 tertiariis. 



Habit. : Secundum Brocchi litus Etruscum incolit (Philippi); Adria: Ve- 

 nezia (G. v. Martens), 



Sphenia Turt. Siphoncs elonr/ati, crassi, uniti, fiinhriati ; pes parms angustus, 

 suhcyJindricus, suJco hi/ssifcro; tcsta inaequivaJms, inacquiJafera, rostrafa, posticc hians, 

 rugosa; vaJva dcxfra paidJo major; cardo cJcxfra dcnficido parvo pjostico, sinistra pri- 

 cessu cochJcarifonni projicicnfc. 



1. Sph. Binghami Tuet. (Mi/a Uinghami Jeffe., Corhida BiiighamiHk^sij.). 

 Testa parva, cuneiforniis, inaequilatera, solidula, concentrice striata, sub epiderniide 

 fusca rugosiuscula alba; margo anterior truncatus, ventralis rectiusculus , pars 

 postica cuueiformis, carina ex umbone decurrente, umbones parvi. — Long. 10, 

 alt. 5 mm. — Forma variat secundum locos. 



Distrib. : Atlauticum medium. — Fossilis in stratis tertiariis. 



Habit. : 5 — 25 org. prof. ; Alger (Weinkaufe); sinus leoninus (Maktin), 

 Toulon (Locakd), Porquerolles (Dubreuil); litora pedemontana (Jeffbeys); Spezia 

 (Tappaeone-Caxefri); Napoli (Jeffreys) ; Tunis (McAndrewj. 



Corbula Bruu. Pallii margines papiJJosi; siphones hrcves uniti, tenfacuJis 

 conicis munifi ; orificium aiiaJe vaJvuJa tubidosa muiiifum, hranchiaJc fimhriafum ; pes 

 magnus acuminafus, sidco <ft cavo hijssogono niunitus; hranchiae leviter striatae ; testa 

 iiiaequivaJvis, epidermide tecta, ovato-triangida, suhinaequiJatera, umhones 'opisthogijri ; 

 dcns primdrius in ufraque vaJva conicus , curvtis , ascendens , fovea lateraJi adjecta ; 

 dentes lafcrales inilli aut vcsfigia tantum corum ; ligameiifum infernum infoveis inscrtum. 



1. C. gibba Jeffr. {TcIIina gihlxi 0\a\i, Mi/a inacquivaJvisMTu., C. olympia 

 CosTA, C. nuclcus Lam., C. striata S. Wood, var. : C. rosea Brown, C curta Loc). 

 Testa gibba, inaequivalvis , valva dextra major convexior sinistram fere phmam 

 maxima ex parte amplectens, ovato-trianguhi, antice rotundata, postice producta, 

 subrostrata , apice trujicato , margine ventrali arcuato , dorsali utrinque declivi, 

 umbonibus, imprimis dextro, i^rominulis et tumidis, incurvatis, antenvedianis; valvae 

 soliduhie albae, interdum fasciis roseis radiantibus ornatae, concentrice dense 

 striatae, epidermide fusca tectae; cardo sat fortis, dente primario singulo, dextro 

 valido recurvo, sinistro humiliore et pro cartihigine profundius excavato, latera- 

 libus dextra ambobus distinctis, sinistra obsoletis. — Long. 12 nim. 



Distrib. : Atlanticum ; ins. Canariae ; maria Europaea; Propontis. 



Habit. : — 130 org. prof. ; litora Hispaniae : Gibraltar, Mahiga (McAn- 

 dkew), Valencia, Mataro, Barcelona (Hidaloo), Cartagena (Jeffreys); ins. balear. : 

 Mahon (McAndbew, Lacaze-Duthiers, Hidalgo), Iviza, Ciudadela (Hidalgo) : 



Carus, Fauna mediterranea. II. 10 



