On Stalk-eyed Crustacea. 131 



the sternum • when the ova are exuded they are covered by 

 this sh eld and are besides defended by the beautiful fan-hke 

 swmming feet which also circulate the water through the mass 

 o7TJ^s In the Anomoura, the hermit crabs, Pagurtda, 

 livin? as they do in the dead shells of Mollusca obtam this 

 somewhat remarkable and artificial protection for their young 

 ThTMACRURA having the abdominal somites developed into 

 arched processes, are furnished with a double row of swim- 

 merets between which the ova are securely carried ; the ova in 

 SS tribe arf^sually attached by very strong ligatures, thus 



nt^"vfill tw bneCoS^r the ova or spawn of these 

 annals! not^nT any particular points of interest that present 



%Tet::a?St%?e:ukbut there are exceptions to 

 thil ^ai: for the ova o'f the C..«.^.»;.^J. are oval m shape 

 whikt those of the Pagundce are slightly so, but cioseiy 

 rp;roach"g thl circular fim, as also are the eggs oi Homarus 



" The'cdour is generally golden, pale brown, or of an amber 

 tint and it is worthy of remark that the colour of the ova is 

 certainly regulated to some extent by that of the parent 

 Cms tacean For example, that of Portumnus vanegatus, ^n 

 anTmal o? a pale tawny ?int and inhabiting sand banks, being 

 of a very light straw colour, that of Xanthoflonda, an anima 

 of a warm ?eddish-brown tint, being of a rich golden, and that 

 oiclrcinus mcenas, an animal of a very variable tint, but 

 usually of a brownish green, being precisely similar in colour 



*°TherTTre, however, one or two remarkably striding 

 exceptons to this rule; the ova for instance, oi Pandaius 

 annul corlis (the Thames "red shrimp,") are of a brilliant 

 Xegreentint,andthoseofPa5si...i.arfa,analmostivorywhite 



crustacean, are of an aqueous colourless appearance. 



The manner in which the eggs are exuded and arranged 

 in symmetrical groups on the swimmerets is difficult to 

 ascertain, and as the females of most species retire either to 

 5^fn wTter or to hiding places, at this period, very little is 

 SnowiTon this point, but if we remove one of the swimming 

 feet and a grou^P of ova from the abdominal segments and 



SmTne the'm un'der a low power f f?^,^J^rj-P,^baLr?oTnt 

 of dark -round illumination, we shall find that the basal joint 

 or coxopodite of the swimmeret supports, as well a transparent 

 stalk branching out into smaller and still smaller processes, 

 and at the en^d of each of these minute stems is fixed an 

 ovum so that each swimmeret thereby protects one bunch of 

 ova and supplies the young with oxygen by setting up a 



