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From the Proceedings of tbe California Academy of Sciences, October IDtli, 1874. 



>*^.v/. 



Observations on the Genus Caprella, and Description of a New 



Species. 



BY W. N. LOCKINGTON. 



Among the Telradecapoda, or foiirteen-legged crnstaceans, the best known 

 forms of which are the pill-bugs, wood-lice, and sand-hoppers, there is no more 

 remarkable genus than Caprella. The abdomen is obsolete, or so nearly so 

 as only to be distinguishable by a most careful examination ; and the entire 

 body consists of the seven thoracic segments, each of which is exceedingly 

 attenuated, so that the creature resembles, in its general appearance, a long, 

 slender caterpillar more than a crustacean. 



Although classed with the fourteen-legged Crustacea, the Cofrella, like their 

 near relatives, the Cyami, or whale-lice, have really only five pairs of legs, as 

 those pairs which normally spring from the third and fourth segments are 

 absent, their place being filled, in the males, by two pairs of elongated bran- 

 chiae. In the females these branchiaj are modified in form and function, becom- 

 ing four broad plates, which fold securely over each other on the lower side of 

 the third and fourth segments, and thus composing a sac or pouch in which the 

 eggs and immature young are safely carried. 



The comparatively great length of the body is still further increased by the 

 long, slender, external antennae, and the backward direction of the hindermost 

 legs ; and the resemblance to a caterpillar is heightened by the mode of pro- 

 gression, which, on account of the absence of legs on the third and fourth seg- 

 ments, is by looping the body in a manner precisely similar to that practiced by 

 the " loopers," or larvae of the Gcometrulos. 



