MOULTING OF THE LOBSTER. ■ 85 



matter. Crabs also have the power of finding their way 

 back to their original habitat when carried off even for 

 several miles. 



The lobster spawns from March till November; the 

 young are hatched with much of the form of the adult, not 

 passing through a metamorphosis, as in most shrimps and 

 crabs. They swim near the surface until about one inch 

 long, afterwards remaining at or near the bottom. 



Tlie lobster probably moults but once annually, during 

 the warmer part of the year, after having nearly attained 

 its maturity, and when about to moult, or cast its skin, the 

 carapace splits from its hind edge as far as the base of the 

 rostrum or beak, where it is too solid to separate. The 

 lobster then draws its body out of the rent in the anterior 

 l^art of the carapace. The claw — at this time soft, fleshy, 

 and very watery — is drawn out through the basal joint, 

 which is partly absorbed to allow the flesh to pass through 

 the joint. In moulting, the stomach, with the solid teeth, 

 is cast off with the old integument. 



Cedehs of Ckustacea. 



Order 1. Feet leaf -like, body usu- 

 ally with a bivalve shell Branchiopoda : Brine Shrimp, etc. 



Order 2. Small, active, with free 

 limbs; some parasitic Entomosiraca : Cyclops, Fish-lice. 



Order 3. Large, fixed, body pro- 

 tected by a shell of several 

 pieces Cirripedia : Barnacles. 



Order 4. Body flat or compressed; 



no carapace; eyes sessile Teiradecapodu: Pill-bug, Beach-fleas. 



Order 5. Thoracic feet leaf -like; 



thorax covered by a carapace . , PJiyllocarida : Nebalia. 



Order 6. Body partly covered 

 with a largd carapace ; feet 

 with gills; eyes stalked Tlioracostraca : Shrimps, Crabs. 



LiTBKATijEB. — Milne-Edwards, Histoire Naturelle des Cnistaces. 

 3 vols. 1834^0.— Dana, Crustacea of the U. S. Exploring Expedi- 

 tion. 2 vols. 1853. — Oerstaeeker, Arlhropoden (in BrODu's Classen 

 und Ordnungen des Thierreichs, 1866-91. 2 yo\s. —Suxley, The 

 Crayfish, 1880.— Packard, Monograph of North American Phyl- 

 lopod Crustacea, 1883.— Also the writings of Say, Dohrn, Sars, 

 Claus, Brooks, Hagen, Faxon, Smith, Kingsley, etc. 



