CHAPTER VI 



CRUSTACEA {CONTINUED) EUMALACOSTKACA {CONTINUE!)) 



EUCAKIDA EUPHAUSIACEA COMPOUND EYES DECAPODA 



DIVISION 4. EUCAEIDA. 



The carapace, fuses with all the thoracic segments. The eyes 

 are pedunculate. The mandible is without a lacinia mobilis. 

 There are no oostegites, the eggs being attached to the endo- 

 podites of the pleopods. The hepatic caeca are much ramified, 

 the heart is abbreviated and saccular, the spermatozoa are 

 spherical with radiating pseudopodia, and development is typically 

 attended by a complicated larval metamorphosis. 



Order I. Euphausiacea. 



The Euphausiidae ^ agree with the Decapoda in passing 

 through a complicated larval metamorphosis. The young hatch 



out as Nauplii, with 

 uniranious first an- 

 tennae and biram- 

 ous second antennae 

 and mandibles. In 

 the next stage, or 

 " Calyptopis " (Fig, 

 101), which corre- 

 sponds exactly to 

 the Zoaea of the 

 Decapoda, two pairs 

 of maxillae and a 

 pair of Itiramous luaxillipedes are added ; the hinder thoracic 

 segments are undifferentiated, but tlie abdomen is fully segmented, 



' Sar.s, Challenger lleports, xiii., 1885 ; Chun, Ilihliotkcca Zoologica, xix., 1896, p. 139. 



144 



P'lri. 101. 'CA\y\^to\n>i\!M-va.oi EiiplMusiapellucida, x about 

 20. AJ, 1st aiitt'iiiia ; Ab.O, 6tli abdominal segment ; 

 A', eye ; 31, ma.xillipede. (After Sar.s.) 



