Long -forgotten British Lithobius. * 373 



Measurements. — Total length of body 35 millim., of antennas 

 15 millim., of anal leg 16\5 millim. 



This specimen is the largest known example of the species. 

 Porath gives 24 millim. as the greatest length of his typical 

 examples and Dr. Meinert assigns 21 millim. to hii specimen 

 from Madeira and 18 to the one from Marocco. In addition 

 to the individual just described and the types of Sloanei and 

 pilicornis, the British Museum possesses a fourth from Ma- 

 deira, which was sent by Mr. J. Y. Johnstone. This measures 

 26 millim. The type of Sloanei has the body very much 

 shrunken ; but, judging from the size of the head and from 

 the length of the anal leg, it was at least as large as this 

 example from St. Michael's Mount. 



The types of pilicornis and Sloanei^ as above stated, possess 

 eight maxillary teeth ; the specimen from St. Michael's 

 Mount has ten, whereas the example from Madeira has but 

 seven, the external tooth on the left side being absent. All 

 of them agree in presenting 2, 2, 1 spines on the under sur- 

 face of the first pair of legs. 



The coxal pores vary a little in number, being either 8, 10, 

 10, 8 or 8, 9, 9, 7. The shape varies also. In the type of 

 Sloanei and in the example from St. Michael's Mount, the 

 two largest of the specimens, they are considerably more 

 elongate than in the others. 



The antennal segments vary in number from thirty-two to 

 thirty-four*. 



Distribution. — As may be inferred from what has been said 

 above, the only definitely known localities for this species are 

 Marocco, Madeira, the Azores, and St. Michael's Mount, off 

 the south-west coast of Cornwall. But we may safely con- 



* Since sending the above to press T have discovered other specimens 

 of this species in the Museum collection. One of these was collected by 

 Mr. Oldtield Thomas at Falmouth, aud had been mistaken for forjicatus 

 until critically examined ; the others, four in number, were obtained by 

 the officers of H.M.S. 'Challenger' at Teneriffe, and, being badly pre- 

 served and damaged, had been provisionally set aside as unidentifiable. 

 Of these Teneriffe specimens only one has a perfect antenna, which proves 

 to be composed of thirty-three segments. In the largest specimen the 

 maxillary teeth are large, sharp, and eight in number j in the others, 

 however, these teeth are very blunt and more or less fused. The example 

 from Falmouth has thirty antennal segments on one side and thirty-five 

 on the other, and the maxillary teeth are conspicuous and four on each 

 side. 



No doubt the species has been introduced into Teneriffe from the 

 mainland, just as it has into Madeira and the Azores; and what has been 

 said above with regard to the distribution of the specimen from St. 

 Michael's Mount will apply equally well to the one from Falmouth. 



Ann. & Mag. N. Hist. Ser. 6. Vol. vii. 26 



