332 THE ANATOMY OF INVERTEBRATED ANIMALS. 



distinct, and the testes and ovaria are lodged in the legs and 

 open upon their basal joints. 



Fig. 91.— Ammothea pycnogonides, female (after Quatrefages).— a, oesophagus; d, 

 antennae ; 6, stomach with its prolongation into the antennas and limbs e • c, 

 rectum. 



The embryo emerges from the egg as a larva provided with 

 a rostrum, and with three pairs of appendages, which repre- 

 sent the short, anterior three pairs in the adult. 1 The four 

 pairs of great limbs of the adult are produced by outgrowths 

 from a subsequent posterior elongation of the body. 



The comparison of the embryos of the Pyenogonida with 

 those of the Acarina, especially such as leave the egg with 

 three pairs of appendages, appears to me to leave little doubt 

 that the rostrum of the larva Pycnogonum is formed, as in 

 the Mites, by the coalesced representatives of the chelicerae 

 and pedipalpi. If so, the seven other pairs of limbs are, by 

 three pairs, in excess of the number found in any Arachnidan. 



1 A. Dohrn, " Untersuehungen iVber Bau und Entwickelung der Arthro- 

 poden." Erstes Heft. 1870. 



