552 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



First Zoea :* — The first and second maxillipedes 

 are developed and their exopods bear four feathered 

 setae (fig. 56, PI. VI). No thoracic limbs are present. 

 The telson has four articulated and two telson spines on 

 either side of the median notch (fig. 48). Only five 

 abdominal segments can be distinguished, the sixth is 

 fused with the telson. 



Second Zoea. — Three maxillipedes are present 

 and the rudiments of the thoracic limbs have appeared. 

 Exopods of maxillipedes have six setae. The " anlagen " 

 of the uropods present in early stages, and in late ones 

 the rudiments of the limbs may be seen through the 

 integument. Two extra spines appear on the telson 

 (fig. 51). 



Third Zoea . — The exopods of the maxillipedes 

 have seven or eight setae and the uropods are present. 

 The sixth segment of the abdomen is distinct. Gill 

 rudiments are present on the limbs. 



Fourth Zoea (Metazoea) (fig. 47). — The thoracic 

 limbs are quite distinct and the fifth pereiopod, which is 

 tucked up under the body, is chelate (fig. 50). The cheli- 

 pedes are unequal. Rudimentary pleopods are present. 



In organisation the Zoea stages do not differ from 

 the others of their type among the Brachyura and 

 Macrura, but in the next stage a complete meta- 

 morphosis is undergone and the great modifications in 

 the structure of the adult Hermit Crab make their 

 appearance. 



The Glaucothoe was for a long time ranked as a 

 distinct species of animal, chiefly because of its com- 

 parative scarcity. The scarcity was only apparent, 

 however, because of the habits of the animal, and when 



* Figures of the Zoeas and Glaucothoe of E. longicarpus may be 

 found in Thompson's valuable paper (quoted above) and in : Faxon, 

 Embryological Monographs, 1. Crustacea. Mem. Mus. Comp. Zoo 1 .-, 

 Harvard, Vol. IX, No. 1, 1882. 



