ARMADILLIDIUM ALBUM; RARE WOODLOUSE. 153 
Terrestrial Isopod Crustacea. Figures are there given of the 
different species, and show at once how very distinct this 
creature is from all other European species of the genus. It 
will therefore be better to briefly mention a few of. its chief 
characteristics rather than make difficult comparisons, as a 
comparison with another species always suggests—to me, at least ° 
—a closer affinity than is very often the case. The body is 
strongly convex, dull, and has the dorsal surface closely granular 
and sparsely set with minute hairs. The frontal cephalic lobe is 
low, narrowly extended and very broad, the side lobes. being 
comparatively small. The antenna is short, covered with hairs, 
and has the last joint of the flagellum more than three times the 
length of the basal joint. The first segment of the mesosome 
does not extend laterally beyond the head. The last segment of 
the metasome is much broader than long, and has the extremity 
broadly rounded; the outer ramus, too, is much broader than 
long, and is armed with a distinct tooth at the outer apical corner, 
whilst the inner ramus is very short, comparatively broad, and 
truncate. The colour, according to Dollfus, is of a uniform 
white,* but one or two of Mr. Cummings’s specimens have the 
segments of the mesosome partially shaded with grey. 
I am told that a specimen of this species, taken by Mr. C. A. 
Briggs, of Tynmouth, was sent to Mr. A. M. Webb for identifica- 
tion, and returned as the common A. vulgare. If no mistake has 
been made in my information, I am compelled, with all due 
respect to Mr. Webb, to differ. In size, colour, character of 
dorsal surface, and structure the two species—album and vulgare 
—have absolutely no conceivable point in common which could 
lead to the one being mistaken for the other. 
In his paper last cited, Dollfus writes :—‘‘ Cette petite espéce, 
Si singuliére, m’a été par M. Gaillard, qui l’avait recue d’Arca- 
chon, en Mars 1886, sans designation spéciale d’habitat. Au 
mois d’Octobre de la méme année, j’en ai trouvé moi-méme 
trois exemplaires, sur la plage d’Arcachon, sous une planche 
échouée devant Saint-Ferdinand; depuis et maleré des recherches 
répétées il m’a été impossible d’en retrouver un seul echan- 
tillon. Peut-étre s’agit-il d’une espéce introduite et qui ne si 
sera pas acclimatée.”’ 
* * Heuille des Jeunes Naturalistes,’ ser. iii. 1892. 
Fie 4th ser. voi. XII., April, 1908. N 
