CHAPTER VI 



CRUSTACEA {CONTINUED} EUMALACOSTRACA (CONTINUED) : 



EUCARIDA 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 l agree with the Decapoda in passing 

 through a complicated larval metamorphosis. The young hatch 



out as Nauplii, with 

 uniramous first an- 

 tennae and biram- 

 ous second antennae 

 and mandibles. In 

 the next stage, or 

 " Calyptopis " (Fig. 

 101), which corre- 

 sponds exactly to 



Fie. 101. Calyptopis larva of Eiqthausia peliucida, x about the Zoaea of the 

 20. A.I 1st antenna ; Ab6 6th abdominal segment ; D ec apoda, tWO pairs 

 A, eye ; M, maxillipede. (After Sara.) 



of maxillae and a 



pair of biramous maxillipedes are added ; the hinder thoracic 

 segments are undifferentiated, but the abdomen is fully segmented, 



1 Sars, Challenger Reports, xiii., 1885 ; Chun, Bibliotheca Zooloyica, xix., 1896, p. 139. 



144 



