53G 



ZOOLOGY 



SECT. 



lated stalks. The antennules 



The eyes (a) are large, compound, and raised on movably articu- 



) and antennae ( 2 ) are large, the 

 mandibles (md.) have palps 

 (mt), and the exopodite of 

 the second maxilla (mxt) 

 has the form of a slender 

 filament which acts as a 

 " cleaning-foot " to keep the 

 cavity of the carapace free 

 from foreign bodies. There 

 are eight thoracic append- 

 ages ( brf ), all of them leaf- 

 like, and recalling those of 

 Apus. The first four abdo- 

 minal appendages {pi pjf) 

 are large biramous swim- 

 ming-feet, like those of 

 Copepods; the fifth and 

 sixth (p5, pG} are small 

 and uniramous. 



The Miizopoda (Fig. 423) 

 are small transparent, 

 shrimp-like forms, mostly 

 from 2-6 mm. in length. 

 They agree with the Crayfish 

 in the general form of the 

 bod}', in the union of the 

 head and thorax, in the 

 presence (except in Ana- 

 x'li/les) of a carapace which 

 may, however, leave some of 

 the posterior thoracic seg- 

 ments uncovered and in the 

 number both of segments 

 and appendages, but present 

 several interesting charac- 

 ters indicating a lower grade 

 of organisation. One of the 

 most notable of these is the 

 absence of differentiation in 

 the thoracic appendages, 

 which have a leg-like and 

 not a leaf-like form, but 

 which are all alike, none of 



tern being modified into maxillipedes, except to a very slight 

 m some forms. Moreovui- the legs all possess exopodites 



Fio. i-'.-Nebalia geoffroyi, male. , eye- 

 ai.antennule : .<._,. antenna ;,. head; I,,T\ thoracic 

 feet; ./, intestine; I,, lu-art ; i-m, gizzard ; ->,!. 

 mandible; mt, niainliiiular palp; mnt. ex..- 

 ipi'ditu ..f second innxilla; ri J>4 . pleopods ; 

 r. n. strum; #, earuparr ; .,,. addiictni- mus 1. : 



/. testis; / ^///, thoracic si/Kim. 

 Lang's Comparatm Anatomy, aftur 



