COMPENDIUM OF GENERIC DISTINCTIONS. 



(.33 



Genus. Acaxthoxyx. — Beak short, deeply cleft; claw-limbs 

 »a:all, all the toes sharply hooked. Six segments in abdomen 

 ui male. Mediterranean. 



Genus. Huexia. — Lower edge of forehead sharp. Hinder 

 feet slightly keeled on front edge. Japan. 



Family. PARTHENOPIDiE.— First pair of legs much larger 

 than others, large, and stout. Carapace triangular. 



Genus. Parthexope. — First pair of feet elbowed at claws. 

 Beak short. Abdomen with seven joints. Warm seas. 



Genus. IiAMBRUS. — Abdomen of male with five joints; rest 

 like Farthenope. Warm and hot seas. 



Genus. Cryptopodia. — Carapace wide; limbs capable of con- 

 cealment under shell. Japan. 



Genus. Euryxome. — Beak with two triangular horns. Ab- 

 domen with seven joints. Eyes retractile. Carapace rough. 

 First joint of outer antenna? ending at inner corner of orbit. 

 Many seas. 



Tribe. CYCLOMETOPITA— Carafe wide, bow -like in 

 front, narrower behind. 



Family. CANCERID.E. — Carapace wider than long. Legs 

 not adapted for swimming; hind-legs with pointed and claw- 

 like toes. 



Genus. Cancer.— Sides of carapace in front, many-lobed. 

 Inner antennse folded longitudinally. Many seas. 



Genus. »Ethra. — Carapace much flattened; claw-feet incapa- 

 ble of being raised perpendicularly. Mauritius. 



Genus. Xaxtho. — Back rather flat. Abdomen with seven 

 joints in female, five in male. Inner antenna? transversely 

 folded. 



Genus. Perimela. — Carapace about as long as broad. Ab- 

 domen as in last genus. Outer jaw-feet with fourth joint in- 

 serted into third of its inner legs. Many seas. 



Genus. Pilumxus. — Carapace convex and hairy. First joint 

 of outer antennae small; four hinder pairs of legs hairy. Many 

 seas. 



Genus. JEcle i including Zozyjius). — Carapace wide, toothed 

 in front. Claw-limbs strung; legs broad and rather flattened. 

 Indian seas. 



Genus. Carpilius. — Carapace round, smooth, sparely toothed 

 in front, wider than long. Claw-s very large and powerful; legs 

 moderate. Mauritius. 



Genus. Galexe. — Cephalothorax slightly bowed in middle; 

 right pincers largest in both sexes; front legs squared. Hot seas. 



Family. P0RTUNID5:.— Last pair of feet flattened, the toe 

 developed into a thin oval plate. 



Genus. Carcixup. — Carapace nearly as long as wide, front 

 projecting. Tarsi of hinder legs narrow - . Many seas. 



Genus. Porttxih. — Carapace broader than long. Abdomen 

 of male triangular. Second to fourth pairs of legs with long, 

 narrow-grooved tarsus. Many seas. 



Genus. Neptuxxs. — Carapace much broader than long, 

 sharply toothed in front, developed into spines on each side. 

 Tarsi of hind-legs very wide. Warm seas. 



Genus. Li'PA. — Carapace wide and pointed at sides. Claw- 

 legs very long, claw slender. Hinder feet flat and broad. 

 West Indies. 



Genus. Polybixs. — Carapace nearly circular. All legs flat- 

 tened, tarsi of fifth pair oval. Many seas. 



(Anns. Pudopthalmus. — Carapace flat, very wide. Claw- 

 feet large and long. Footstalks of eyes enormously long and 

 moveable, resting in groove when not raised. Claws short. 

 Mauritius and Philippines. 



Tribe. GA TOMETO ri TA.— Carapace nearly square or oval, 

 front nearly straight. Eves on long footstalks. 



Family. THELPHUSIDJE.— Carapace more or less oval. Eye- 

 footstalks short; fourth joint of jaw-feet not inserted into ex- 

 ternal angle of preceding. 



Genus. Thelphcsa.— Carapace flat, smooth, broad, and 

 heart-shaped. External antenna? very short, placed near foot- 

 stalks of eyes. Warm seas. 



Family. GECARCINIDJE.- Carapace wide, thin, long, or 

 rounded. Eye-footstalks long; fourth joint of jaw-feet inserted 

 into external angle of preceding. 

 Vol. in.— 80. 



Genus. Gecarcints. — Carapace heart-shaped, broad in front, 

 stout, blunt behind. Footstalks of eyes short, lying in rounded 

 furrows. South America. 



Family. PINNOTHERIDiE.— Carapace circular, front mostly 

 narrow. Eye-footstalks very short; fourth joint of jaw-feet 

 springing from top or outer angle of third joint. 



Genus. Pixxotheres. — Inner antennse concealed under front 

 of carapace. Body circular, rounded above. Abdomen of male 

 very small, of female large and swollen. Many seas. 



Family. MYCTIEIDa:.— Carapace rather triangular. Body 

 lamellated. Beak small, under which the eyes lie concealed. 

 Sternal plate wider than long. 



Genus. Myctiris. — Carapace delicate, convex, rather circu- 

 lar or narrower in front. Limbs long and slender. Claw-feet 

 long. Warm seas. 



Family. OCYPODIDiE. — Carapace rhomboidal, elevated in 

 front. Eye-footstalks long. Claws very unequal in size. 



Genus. Ocypode. — Eyes occupying greater part of foot- 

 stalks. Abdomen of male very narrow, last joint triangular; 

 that of female is oval. West Indies. 



Genus. Gelasimus. — Last segment of abdomen in male semi- 

 circular, in female nearly round. Hot seas. 



Family. G0N0PLACID.E. — Carapace rhomboidal, front mar- 

 gin and sides forming continuous lines. Front very wide. Outer 

 antenna? lodged below front and horizontal. Eve-footstalks 

 very long. 



Genus. Goxoplax. — Carapace very wide in front. Eye-foot- 

 stalks inserted near middle of front, very long, slender, reach- 

 ing to front angles. Claws in males long and cylindrical. 

 Abdomen of both sexes witli seven joints. Temperate seas. 



Family. GRAPSIDiE.— Body compressed. Eye-footstalks 

 short, thick, the eye occupying half their length. Front limbs 

 short. 



Genus. GraPSUS. — Carapace not narrower in front than be- 

 hind. Middle antenna? lodged under front. Hot seas. 



Genus. Plaxes. — Carapace longer than wide, front project- 

 ing. Tarsi thick and spined. Temperate and warm seas 



Tribe. OXTSTOUATA.— Outer jaw-feet when (dosed form- 

 ing a triangular point. Outer antenna? very small. 



Family. CALAPPIDJE. — Last four pairs of feet concealed un- 

 der carapace, first pair folded and coinciding with the general 

 outline. 



Genus. Calappa. — Antenna? like those of Cancer. Claws 

 very large, compressed, and notched at upper edge, folded so 

 as to cover mouth. Warm and hot seas. 



Genus. Theai.ia. — Carapace rounded, with projecting spikes 

 at sides and back. Legs rather long. China. 



Genus. Camara. — Carapace round, smooth and wide, simple 

 at edges. Claw-feet very flat. Mauritius. 



Family. LEUCOSHDiE.— Outer jaw-feet when closed sharp- 

 pointed and triangular in front. Carapace more or less circular. 

 No branchial openings before front-legs. 



Genus. Leucosia. — Internal antenna? in little pits. Eyes 

 small. Shell solid. Hot seas. 



Genus. Myra. — Carapace rather egg-shaped. Front limbs 

 long. Indian seas. 



Genus. Ixa. — Carapace wider than long, sides prolonged into 

 cylinder or cone. Philippines. 



Genus. Iphis. — Carapace rhomboidal. Conical spurry points 

 on each side. Philippines. 



Genus. Ebalia. — Carapace rhomboidal, knobbed. Abdomen 

 seven-jointed, in male narrow, in female broad; last joint very 

 small. Temperate and warm seas. 



Genus. Ni'rsia. — Carapace rhomboidal, sides angulated or 

 scooped. Indian Ocean. 



Family. CORYSTIDS;.— Outer antenna? very large. Sternal 

 plate long and narrow. 



Genus. Coryptes. — Carapace longer than wide, with a few 

 teeth, front forming a beak. Outer antennse longer than cara- 

 pace, with row of long hairs on upper and lower edges. Fore- 

 legs of male very long. Temperate and warm seas. 



Genus. Tuia. — Carapace smooth, heart-shaped, narrow behind, 

 front projecting, All legs small. Temperate and warm sens, 



