7D6 



COMPENDIUM OF GENEEIC DISTINCTIONS 



CLASS-CRUSTACEA. 



Ringed animals, with horny or calcareous exterior ; limbs 



articulated Respiration by gills or skin; sexes sepa- 

 rate. 



Sub-class. PODOPTHALMATA. Eyes on 

 moveable footstalks. 



Order. DECAPODA. Walking legs ten. Mouth-limbs 

 twelve. Gills on side of carapace. 



Hub-order. BRACHYUEA. Abdomen very small, folded 

 under the body. 



Tribe. OXYRHYNCHITA .Carapace narrow in front, 

 and forming a beak. Mouth apparatus squared. 



Family. MACROPODIADJE. Legs long and slender, 

 second or third pair larger than first. 



Germ*. STENOKHYNCHUS. Carapace triangular, pro- 

 longed into two-forked beak. Eyes not retractile. First 

 joint of outer antennae narrow, third larger than second. 

 Abdomen six joints. Many seas. 



Genus. LEPTOPODIA. Claw-legs well developed, short. 

 Antennae feathered. West Indies and warm seas. 



Genus. CAMPOSCIA. Carapace smooth ; claw-legs small ; 

 limbs with stout bristles. Antennae short and partly 

 feathered. Mauritius. 



Genus. DOCLEA. Beak small ; claw-limbs large and 

 powerful ; carapace with many long and stout spines. 

 Hotter seas. 



Family. MAIAD&. Legs moderately long, first pair 

 often larger than following ; base of outer antennae large. 



Genus. LISSA. Beak wide, notch shallow. Claw-legs 

 moderate. Carapace and limbs noduled. Warm and hot 

 seas. 



Genus. CHOIUNUS. Body large and rounded ; limbs 

 rather short ; beak long. Limbs, and sometimes body, 

 noduled or spined. West Indies. 



Genus. ARCTOPSIS. Carapace triangular, front with four 

 horns, the two central forming a beak. Eyes on short 

 footstalks. Abdomen seven joints. Many seas. 



Genus. HYAS. First joint at base of outer antennre 

 flattened and widened on outer side. Carapace wide and 

 flat. Many seas. 



Genus. MAIA. Moveable stem of outer antennae within 

 corner of orbit. Carapace oval, beak stout. . First pair of 

 legs scarcely larger than others. Abdomen with seven 

 joints. Most seas. 



Genus. MICIPPA. First joint of outer antennae bent t\nd 

 widened at upper end. Carapace truncated in front, and 

 terminated by a toothed bill. Philippines. 



Genus. PERICERA. Lateral antennae inserted under 

 muzzle. Seven segments in abdomen. West Indian seas. 



Genus. CRIOCARCINUS. Beak bifid, very long, and 

 diverging. Eyes on long footstalks. Claw-limbs large ; 

 carapace spinose. New Hebrides. 



Genus. ACANTHONTX. Beak short, deeply Jeft; claw- 

 limbs small, all the toes sharply hooked. Six segments in 

 abdomen of male. Mediterranean. 



Genus. HUENIA. Lower edge of forehead sharp. Hinder 

 feet slightly keeled on front edge. Japan. 



Family. PARTHENOPIDJE. First pair of legs much 

 larger than others, large, and stout. Carapace triangular. 



Genus. PARTHENOPE. First pair of feet elbowed at 

 claws. Beak short. Abdomen with seven joints. Warm 

 seas. 



Genus. LAMBRUS. Abdomen of male with five joints ; 

 rest like Parthenope. Warm and hot seas. 



Genus. CRYPTOPODIA. Carapace wide ; limbs capable 

 of concealment under shell. Japan. 



Genus. EURYNOMB. Beak with two triangular horns. 

 Abdomen with seven joints. Eyes retractile. Carapace 

 rough. First joint of outer antennae ending at inner corner 

 of orbit. Many seas. 



Tribe. CYCLOMfiTOPITA.C&r&pa.ce wide, bow-like 

 in front, narrower behind. 



Family. CANCEKID.2E. Carapace wider than long, 

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

 claw-like toes. 



Genus. CANCER. Sides of carapace in front, many-lobed. 

 Inner antennae folded longitudinally. Many seas. 



Genus. .55THRA. Carapace much flattened ; claw-feet 

 incapable of being raised perpendicularly. Mauritius. 



Genus. XANTHO. Back rather flat. Abdomen with 



seven joints in female, five in male. Inner antennae trans- 

 versely folded. 



Genus. PERIMELA. Carapace about as long as broad. 

 Abdomen as in last genus. Outer jaw-feet with fourth 

 joint inserted into third of its inner edge. Many seas. 



Genus. PlLUMNUS. Carapace convex and hairy. First 

 joint of outer antennae small ; four hinder pairs of legs 

 hairy. Many seas. 



Genus ^EGLE (including ZozYMOs). Carapace wide, 

 toothed in front. Claw-limbs strong ; legs broad and rather 

 flattened. Indian seas. 



Genus. CARPILIUS. Carapace round, smooth, sparely 

 toothed in front, wider than long. Claws very large and 

 powerful ; legs moderate. Mauritius. 



Genus. GALENE. Cephalothorax slightly bowed in 

 middle ; right pincers largest in both sexes ; front legs 

 squared. Hot seas. 



Family. PORTUNID^l. Last pair of feet flattened, the 

 toe developed into a thin oval plate. 



Genus. CARCINUS. Carapace nearly as long as wide, 

 front projecting. Tarsi of hinder legs narrow. Many 

 seas. 



Genus. PORTUNUS. Carapace broader than Jong. Ab- 

 domen of male triangular. Second to fourth pairs of legs 

 with long, narrow-grooved tarsus. Many seas. 



Genus. NEPTUNUS. Carapace much broader than long, 

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

 Tarsi of hind-legs very wide. Warm seas. 



Genus. LUPA. Carapace wide and pointed at sides. 

 Claw -legs very long, claw slender. Hinder feet flat and 

 broad. West Indies. 



Genus. POLYBIUS. Carapace nearly circular. All legs 

 flattened, tarsi of fifth pair oval. Many seas. 



Genus. PODOPTHALMUS. 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. CA TOME TOP IT A .Carapace nearly square 01 

 oval, front nearly straight. Eyes on long footstalks. 



Family. THELPHUSID^l. Carapace more or less oval. 

 Eye-footstalks short ; fourth joint of jaw-feet not inserted 

 into external angle cf preceding. 



Genus. THELPHUSA. Carapace flat, smooth, broad, and 

 heart-shaped. External antennas very short, placed near 

 footstalks of eyes. Warm seas. 



Family. GECABCINID^E. Carapace wide, thin, long, 

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

 inserted into external angle of preceding. 



Genus. GECARCTNUS. Carapace heart-shaped, broad in 

 front, stout, blunt behind. Footstalks of eyes short, lying 

 in rounded furrows. South America. 



Family. PINNOTHERIDJE. Carapace circular, front 

 mostly narrow. Eye-footstalks very short ; fourth joint oi 

 jaw-feet springing from top or outer angle of third joint. 



Genus. PINNOTHERES.- Inner antennas concealed under 

 front of carapace. Body circular, rounded above. Abdomen 

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



Family. MYCTIRIDJE. Carapace rather triangular. 

 Body lamellated. Beak small, under which the eyes lie 

 concealed. Sternal plate wider than long. 



Genus. MYCTIRIS. Carapace delicate, convex, rather 

 circular or narrower in front. Limbs long and slender. 

 Claw-feet long. Warm seas. 



Family. OCYPODID^l. 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 

 semicircular, hi female nearly round. Hot seas. 



Family. GONOPLACID5!. Carapace rhomboidal, front 

 margin and sides forming continuous lines. Front very wide. 

 Outer antennae lodged below front and horizontal. Eye-foot- 

 stalks very long. 



Genus. GONOPLAX. Carapace very wide in front. Eye- 

 footstalks inserted near middle of front, very long, slender, 

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

 Abdomen ,of both sexes with seven joints. Temperate 

 seas. 



Family. GRAPSIH33. Body compressed. Eye-footstalks 

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

 limbs short. 



