Porcellio laevis Latreille[35]
Porcellio ratzeburgii Brandt[36]
Genus—Metoponorthus Budde-Lund[37]
Metoponorthus pruinosus Brandt[37]
Metoponorthus cingendus Kinahan[38]
Genus—Cylisticus Schnitzler[38]
Cylisticus convexus De Geer[39]
Family—Armadillidiidæ[40]
Genus—Armadillidium Brandt[40]
Armadillidium nasatum Budde-Lund[40]
Armadillidium vulgare Latreille[41]
Armadillidium pulchellum Zencker[42]
Armadillidium depressum Brandt[43]
Distribution of species[43]
Conclusion[43]
Bibliography[45]

[LIST OF FIGURES.]

PLATES I.-XXV. with a List, will be found at the end of the Book.

FIGURE. PAGE.
[1.]Parts of the body (Oniscus asellus)2
[2.]The first antenna (Oniscus asellus)2
[3.]The second antenna (Oniscus asellus)3
[4.]The underside of the head (Oniscus asellus)3
[5.]The mandibles (Oniscus asellus)4
[6.]The first maxillae (Oniscus asellus)4
[7.]The second maxillae (Oniscus asellus)4
[8.]The fused maxillipeds (Oniscus asellus)4
[9.]The "upper lip" (Oniscus asellus)5
[10.]The "lower lip" (Oniscus asellus)5
[11.]A typical thoracic segment (Oniscus asellus)5
[12.]The fifth thoracic segment of a female (Oniscus asellus)5
[13.]The underside of the abdomen of a female (Oniscus asellus)6
[14.]A typical abdominal appendage (Oniscus asellus)6
[15.]The first abdominal appendage of the male (Oniscus asellus)6
[16.]The second abdominal appendage of the male (Oniscus asellus)6
[17.]The alimentary canal (Oniscus asellus)7
[18.]The circulatory system (Oniscus asellus)7
[19.]The nervous system (Oniscus asellus)8
[20.]Female reproductory organs (Oniscus asellus)8
[21.]The male reproductory organs (Oniscus asellus)9
[22.]The fertilized egg (Porcellio scaber) after Roule10
[23.]The fertilized egg seen in section (Porcellio scaber) after Roule10
[24 to 31.]The development of a woodlouse (Porcellio scaber) after Roule10
[32.]Embryo of the woodlouse showing the three divisions of the intestine separately developed (Porcellio scaber) after Roule11
[33.]Embryo of the woodlouse showing traces of the segments (Porcellio scaber) after Roule11
[34.]An embryo woodlouse ready to be hatched (Porcellio scaber) after Roule11
[35.]Flagellum and last peduncular joint of the antenna of Ligia oceanica12
[36.]Flagellum and last peduncular joint of the antenna of Ligidium hypnorum13
[37.]Flagellum and last peduncular joint of the antenna of Trichoniscus pusillus23
[38.]Flagellum and last peduncular joint of the antenna of Trichoniscus vividus24
[39.]Flagellum and last peduncular joint of the antenna of Trichoniscus roseus24

[40.]Flagellum and last peduncular joint of the antenna of Trischoniscoides albidus25
[41.]Flagellum and last peduncular joint of the antenna of Haplophthalmus mengii26
[42.]Flagellum and last peduncular joint of the antenna of Haplophthalmus danicus27
[43.]Flagellum and last peduncular joint of the antenna of Oniscus asellus28
[44.]Flagellum and last peduncular joint of the antenna of Philoscia muscorum29
[45.]Flagellum and last peduncular joint of the antenna of Philoscia couchii30
[46.]Flagellum and last peduncular joint of the antenna of Platyarthrus hoffmannseggii31
[47.]Flagellum and last peduncular joint of the antenna of Porcellio scaber32
[48.]Flagellum and last peduncular joint of the antenna of Porcellio pictus33
[49.]Flagellum and last peduncular joint of the antenna of Porcellio dilatatus34
[50.]Flagellum and last peduncular joint of the antenna of Porcellio rathkei35
[51.]Flagellum and last peduncular joint of the antenna of Porcellio laevis35
[52.]Flagellum and last peduncular joint of the antenna of Porcellio ratzeburgii36
[53.]Flagellum and last peduncular joint of the antenna of Metoponorthus pruinosus37
[54.]Flagellum and last peduncular joint of the antenna of Metoponorthus cingendus38
[55.]Flagellum and last peduncular joint of the antenna of Cylisticus convexus39
[56.]Flagellum and last peduncular joint of the antenna of Armadillidium nasatum40
[57.]Flagellum and last peduncular joint of the antenna of Armadillidium vulgare41
[58.]Flagellum and last peduncular joint of the antenna of Armadillidium pulchellum42
[59.]Flagellum and last peduncular joint of the antenna of Armadillidium depressum43