affecting the Potatocrops. 99 



quadrate and narrow : it has 15 pair of bristly and spiny legs, the 

 hinder pair being the longest, they are 7-jointed, curved, taper- 

 ing, and terminated by a minute conical claw. 



The other species may prove to be the true Scolopendra elec- 

 trica of Linnaeus; it belongs to the Genus Anthronomalus of 

 Newport,* and is certainly Leach's 



25. Geophilus longicornis. This species is from 2^- to 3 inches 

 long, and not more than ^ or f of a line broad. It is shining 

 bright ochreous : the head is oval with a strong jaw on each side 

 terminating in a sharp blackish claw : eyes none ; horns thrice as 

 long as the head, like 2 hairy threads, composed of 14 joints, 

 decreasing to the apex : body composed of a multitude of trans- 

 verse segments, with from 51 to 55 pair of short legs, the hinder 

 pair not longer than the others; the claws long and slender 

 (%.45). 



These creatures move with a very waving motion from right to 

 left, doubling when they turn, and this as well as a few other 

 species have the very extraordinary power of secreting a phos- 

 phoric fluid, which the animal leaves behind as it walks, so that 

 when it is dark one sees a luminous broken line of light, some- 

 times 2 or ^ feet long. This phenomenon is generally noticed 

 in autumn and spring, and is supposed to be most active when 

 the animals are pairing : whether the fluid is secreted by both sexes 

 seems doubtful, and if they be quite blind, the light must be 

 bestowed upon them for reasons which as yet remain hidden from 

 us. Their economy is likewise very interesting, for Mr. Newport 

 has proved that " the female deposits her eggs, from 30 to 50 in 

 number, in a little packet, in a cell which she forms for them in 

 the earth, and never once leaves them until the young are 

 developed, which is at the end of about a fortnight or three weeks. 

 During the whole of this time she remains in the cell, with her 

 body coiled around the eggs, incubating them and constantly 

 turning and attending to them.^'f They hybernate in the earth 

 during the winter, and subsist partly on succulent roots, ripe fruit, 

 and decaying vegetable matter, only coming out at night, appa- 

 rently in search of food. 



We have now arrived at the second section of our subject, 

 relating to the various insects and allied animals which are found 

 amongst the potatoes when decomposition has commenced. They 

 amount to a very considerable number, and yet probably not half 

 of them have been noticed, for whilst those recorded by 

 M. Guerin comprise nine different sorts, the species detected in 

 this country are twice as many. 



In February, 184G, a Podura, probably the P. plumbea of 



* Trans. Linn. Soc.,.vol. xix. p. 430, + Ibid., vol. xix. p. 42.8. 



