EPICARIDA LIFE-HISTORY OF DANALIA 



which is itself parasitic on the spider-crab, Inachus mauritanicus, 

 at Naples. The adult Danalia is a mere curved bag full of eggs 

 or developing embryos, and without any other recognisable organs 

 except two pairs of sper- 

 mathecae upon the ventral 

 surface where jbhe sper- 

 matozoa derived from the 

 larval males are stored. 



In Fig. 86 is repre- 

 sented a female of Inachus 

 mauritanicus which carried 

 upon it two Sacculinae and 

 a Danalia curvata, and 



upon the latter are seen FIQ. 86. Inachus mauritanicus, <}, xl, currying 



two tfoci'tiliiiti neglect/', (a, b), and a Jhtnalia 

 t\\O minute .larval males curvata (c), the latter bearing two dwarf iiKib's. 



in the act of fertilising the 



adult Danalia. The eggs develop into the Epicaridian stage, 

 after which the larva passes into the Cryptoniscus stage (Fig. 87). 

 In this larval form the segments are clearly delimited ; the only 

 mouth-parts present are the mandibles, but there are seven pairs 

 of thoracic limbs and the full number of 

 pleopods. This Cryptoniscus stage is found in 

 all the Epicarida, and only differs in detail in 

 t he various families. 



In the Cryptoniscina the Crypt on isriis larva 

 is the male, and at this stage possesses a pair 

 of large testes in the thorax. The n\aries are 

 also present at this stage as very small bodies 

 applied to the anterior ends of the fcestes. The 

 larval males in this state seek out, adult fixed 

 Danaliae and fertilise them; and, when this is 



accomplished, they 1 hemsel\ es become fixed to 



the host and begin to develop into the adult 

 female condition. The limbs are all lost, and 

 mouth grows a loii^- proboscis i . l-'ig. 

 curvata, 6 , x 25. 88, 7'), which penetrates the tissues of the 



host. Tin- ovaries begin in grow, ami a re- 

 markable process of absorption in the t.estes takes place. Th' 



Fic.87. Vent nil view 



of Cryptoniscus ( , ut/ o f 

 larva nt Danalia 



organs, when fixation occurs, are never empty of 



and are frequently crammed with them. After fixation some 



