Suborder ~CLADOCERA~ (/Small phyllopoda; body laterally compressed; carapace like a bivalve shell; four to five pairs of swimming-feet; chief organs of locomotion are the biramous antennæ; abdomen devoid of appendages. They abound in fresh water, are very prolific, and afford a large amount of food to fresh-water fishes/) Genera Species ^Daphnia^ ^Leptodora^ ^Moina^ ^Polyphemus^ Order =OSTRACODA= (/Resemble minute bivalve shells; swim by antennæ; body unsegmented; appendages seven pairs only/) ^Cypris^ (fresh-water) ^Cypridina^ (marine) Order =COPEPODA= (/Small size; body long, segmented; four to five pairs of once-branched appendages on thorax; abdomen without appendages; abundant in fresh and salt water; many forms parasitic/) ^Cyclops^ ^Cetochilus^ ^Sapphirina^ ^Siphonostomata^ ^Nicothoë^ Order =CIRRIPEDIA= (/Imperfectly segmented; fixed or parasitic during adult life; inclosed in skin strengthened by calcareous plates; abdomen rudimentary; appendages biramous, usually six pairs/) Genera Species ^Lepas^ ^L. anatifera^ ^L. striata^ ^L. pectinata^ ^Balanus^ ^B. balanoides^ ^B. eburneus^ ^B. rugosus^ ^B. geniculatus^ ^B. tintinnabulum^ Suborder ~RHIZOCEPHALA~ (/Parasitic/.) ^Sacculina^ (parasitic on crabs) ^Peltogaster^ (parasitic on hermit-crabs) Subclass =Malacostraca= (/Highly organized Crustacea, usually of considerable size; appendages much differentiated/) Order =PHYLLOCARIDA= (/Small; covered with bivalved carapace; thoracic feet leaf-like; abdominal feet biramous; posterior segment terminates in two long spines; mostly fresh-water species/) Order =SCHIZOPODA= (/Small; transparent; shrimp-like; thorax more or less completely covered with soft carapace; thoracic appendages biramous; eyes on stalks/. /Mysis/ are /Without gills or thoracic legs/; /Euphausia/ are /With gills or thoracic legs/.)