MAI.ACOLOGY. 



MALACOLOGY. 



Family Pkotadida. 

 Pholai. Gaitrockirna. 



(ft) Shell without accessory pieces, and gaping at the lateral 

 extremities only. 



Family Solenida. 

 Sole*. Panopaa. Glyeymeru. 

 (b) Ligament internal. 



Family Myida. 

 Mya. Anatina. 



() Tenuipede Conchifers. Mantle with its lobes not united, or 

 hardly united anteriorly ; foot small, compressed ; gaping of the shell 

 often considerable, 

 (t) Ligament internal. 



Family Mactrida. 

 Ligament internal only. 

 Shell gaping on ita aides. 

 Lutraria. Mactra. 

 (b) Shell not gaping at ita sides. 

 CnutateUa. rycina. 



(2) Ligament visible externally, or double, one part being internal, 

 the other external 



UnjftUina, Solemya. A mphidetma. 



Family Corbulidft. 



Shell incquivalve. Ligament internal 

 CorbtUa. Pandora. 

 (ft) Ligament external only. 



Family Lithophagidte. 



Boring shells without accessory pieces, without any particular 

 sheath, and more or less gaping at their anterior side. Ligament of 

 the valves internal. 



Saj-icara. Peiricola. Venerupit. 



Family Nyntfhida. 



Two cardinal teeth at most in the same valve. Shell often gaping 

 a little at the lateral extremities. Ligament external. Nymphs in 

 general gaping outwards. 



(1) Solen-like Nymphida, 

 Sangninolaria. Piammobia. Ptammotaa. 



(2) Tellen-like Nymphida. 



(a) Lateral teeth, one or two. 



Trllina. TMinidf*. Corbit. Lucina. Donax. 



(b) No lateral teeth. 

 Capta. Cratnna. 



(B) Shell closed at the lateral extremities, when the valves are 

 closed. 



(") Lamellipede Conchifers. Foot flattened, lamelliform, not 

 posterior. 



Family Conekidee. 



Three cardinal teeth at least in one valve, with as many or less in 

 the other. Lateral teeth sometimes. 



(1) Fluviatile Conckida. Shell with lateral teeth, and covered with 

 a false epidermis. 



Cyclai. Cyrena. Oalatliea. 



(2) Marine Conckida. No lateral teeth in the greater number; 

 rarely an epidermis, which covers the whole shell except the umboues. 



typrtno. Cytkerea. Ventu. Venericardia. 



Family Cardiidir. 



Cardinal teeth irregular, either in their form or situation, and 

 accompanied in general by one or two lateral teeth. 



Cardnun. C'ardita. Cypricardia. JJiatclla. Iiocardia. 



Family Arcida. 



Cardinal teeth small, numerous, intrant, and disposed in each valve 

 on a line which is either straight, or arched, or broken. 



C*c*llaca. Area. Pectunculut. Nucula. Trigonia. Cattalia. 



Family Naiidir. 



Fluviatile shells, whose hinge is sometime* furnished with an irregu- 

 lar cardinal tooth which is simple or divided, and with a longitudinal 

 tooth which is prolonged under the corselet; and sometimes is with- 

 out any tooth at all, or is furnished along it* length with irregular 

 granular tubercles. 



Muscular impression posterior and compound. Umbones with the 

 epidermis peeled off, and frequently eroded. 



l.'nio. Ifyria. Anodonta (or rather Anodvn). Iridina, 



("") Ambiguous Conchifers. 



Family Chamiilir. 



Shell irregular, inequivalve. A single cardinal tooth, which is 

 oblique and subcrenato, inserted into a little pit in the opposite 

 valve. 



Muscular impressions two, distant, lateral. External ligament 

 depressed. 



JXctrat. C'Aamo. Klheria. 



Order 2. Conchifrra Monomyaria. 



Only one muscle of attachment, which seems to traverse their body. 

 Shell with an internal subceutral muscular impression. 



() Ligament marginal, elongated on the border, nub-linear. 



(a) Shell transverse, equivalve, with an elongated muscular 

 impression bordering the upper limb. 



Family Tridaenida. 



Tridacna. Hlppoput. 



(b) Shell longitudinal or subtransveree, with a muscular impression 

 contracted into an isolated space without bordering the limb. 



(t) Ligament at the lateral border of the shell, and always entire. 



Family Mytilidce. 



Hinge with a subinternal ligament, which is marginal, linear, MTV 

 entire, occupying a great port of the anterior border. Shell rarely 

 foliated. 



Modiola. Myliltu. Pinna. 



(tt) Ligament at the lower border of the shell, or divided. 



Family MaUfida. 



Ligament marginal, sublinear, either interrupted by crenulations or 

 serial teeth, or altogether simple. Shell sub-inequivalve, foliated. 

 Crenattila. Perna. Malleta. Avicvla. Udeayrina. 

 (**) Ligament not marginal, contracted into a short space under 

 the umboues, and not forming a tendinous tube under the shell. 



(a) Ligament internal or demi-internaL Shell regular, com^u-l, 

 not foliated. 



Family Pcctinid<e. 



Pedum. Lima. Plagiostoma. Pecten. Plicattda. Sjioiidyltw. 

 Podoptit. 



(&) Ligament internal or demi-iutemaL Shell irregular, foliated, 

 sometimes papyraceous. 



Family Ottreida. 



(1) Ligament demi-internaL Shell foliated, but neverthelesi often 

 acquiring great thickness. 



Oryphtfa. Oitrea. Vulsella. 



(2) Ligament internal Shell delicate, papyraceous. 

 Placuna. Anomia. 



('") Ligament either null or unknown, or represented by a 

 tendinous cord which sustains the shell. 



(a) Ligament and animal unknown. Shell very incquivalve. 



Family jRudi*' 



Sphrrrulila. Radiolita. Calceola. Sirottritet. Ditcina. Crania, 



(b) Shell adherent, either immediately or by a tendinous cord 

 which sustains it, and serves as a ligament. Animal with two opposed 

 arms, which are opposed, ciliated, and cirrhous. 



Family Brachiopodidac. 



Conchifers having near the mouth two opposed elongated ciliated 

 arms, rolled spirally when in repose. Mantle bilobated, the lobes 

 separated anteriorly, enveloping or covering the body. 



Shell bivalve, adhering to marine bodies, either immediately or by 

 a tendinous cord. 



Orbicvla. Terc>iratuia. Lingula. 



Class XII. MOU.USCA. 



Order 1. Pteropoda. 



No foot for creeping, nor arms for progress or seizing the prey. 

 Two fins opposed and similar, proper for natation. Body free and 

 floating. 



Clio. Clcodora. Limacina. Cymbulia. Pneumodermon. 



Order 2. Oattcropoda, 



Animals with a straight body, never spiral nor enveloped in a ahull 

 which can contain the entire animal ; having under the belly a font or 

 muscular disc united to the body nearly throughout its length, and 

 serving for creeping. 



Some naked, others protected by a dorsal shell, not imbedded ; itnd 

 others, on the other hand, containing a shell more or leu hidden in 

 their mantle. 



Section 1. IfydrobranMata. 



Brancliiec, whatever be their position, elevated either in a net-work, 

 in laminic, in a pectinated form, or in a ribbon-like shape. The 

 animals of this section breathe water only. 



(a) Branchiae external, placed above the mantle, either on the back 

 or on the sides, and being in no particular cavity. 



Family Ti'iloaidte. 

 tilancu*. Kola. Tritonia. Scyllira. Telhyi. Dorit. 



(b) Bronchia placed under the tarder of the mantle, and disposed 

 in a longitudinal series round the body, or on one side only ; not 

 being in any particular cavity. 



Family Phyllidtdtr. 

 Phyllidia. ChUonMu*. Chiton, Patella. 



