440 Mr. George Dickie on the Fumariaceae. 



by contracting and again expanding the abdominal section of 

 its body. These movements soon detach its large tail^ and with 

 it the whole abdominal envelope ; after which the animal uses 

 the most violent exertions^ by means of the now strong spines 

 of its tail, doubling it under its thorax, and throwing it back 

 straight again, with all the force it is capable of, to tear away 

 the covering of the legs. The great majority of the larvae ex- 

 haust themselves and fall victims to their fruitless efforts to ac- 

 complish this portion of the moult ; but having effected it, 

 the antennae and corselet come away also; the dorsal spine, 

 ■which is seen in fig. 1. reclining towards the head, rises up and 

 takes an inclination in the opposite direction ; the frontal spine, 

 which has hitherto been doubled up and concealed under 

 the thorax, unfolds itself; and the little animal swims away 

 with an awkward short movement of its natatory legs, some- 

 times on its back as represented in fig. 3, sometimes on its 

 face as in fig. 4 ; but always with its tail bent under it, ap- 

 proximating to the situation it is destined to be carried in 

 when the animal has attained its adult state. 



The larva of Carcinus Mcenas, it will be observed, in its se- 

 cond stage resembles in its general character that of Cancer 

 Pagurus, figured by Mr. Thompson in the Second Number of 

 his Zoological Researches. They are both as unlike their ori- 

 ginal types as it is well possible to imagine, and the probabi- 

 lity I think is that they have each still to undergo a succession 

 of changes before they become perfect crabs. Having ob- 

 tained the larvae of Carcinus Mcenas from two different speci- 

 mens in such abundance, I entertained great hopes of follow- 

 ing it through all its phases ; none of the larvae, how^ever, sur- 

 vived their birth beyond the fourteenth day, at which time 

 they showed no indications of any preparation for a further 

 metamorphosis. 



Southampton, May 29, 1839. 



L. — Remarks on the Fumariaceae. By George Dickie, Esq., 

 A.L.S., Lecturer on Botany at Aberdeen. 



The characters of the order Fumariacece are generally stated 

 thus : " Sepals two, deciduous. Petals four, cruciate, par- 



