194 DUBLIN UNIVERSITY 



am indebted to my friend, A. H. Holiday, Esq., for the note of its 

 occurrence. Fifteen species of Oniscoids are there described, including 

 this species and Trichoniscus rosem. This last, I suspect, is Itea rosea 

 of Koch — my Philougria rosea — a species, by the way, which, although 

 wanting in the Museum of the Jardin des Plantes, I found (August, 

 1858) to be exceedingly common on the quays, and in other places in 

 the neighbourhood of Dieppe, replacing, in a great degree, Philougria 

 riparia of the British shores. Possibly this species may have been in- 

 troduced from some of the Trench ports into Plymouth. 



In the " Eevue et Magazine de Zoologie, 1853," in some " Observa- 

 tions on two new Genera of Coleoptera, inhabitants of Ant-hills," by M. 

 H. Lucas, mention is made of an Oniscoid found by M. Lucas, accord- 

 ing to a note he kindly furnished me with, "in the neighbourhood of 

 Medeah, in Algeria, under moist stones in ant-hills of Ifyrmica testaceo- 

 pilosa" and which M. Lucas, but without description, has named Por- 

 cellio myrmecophila. Examination of specimens kindly communicated 

 to me by the discoverer proves that the species belongs to a genus 

 nearly allied, in some characters, to Trichoniscus, as described by that 

 author. I have therefore constituted for it a genus, to which I would, 

 from the discoverer of the species, append the name of Lucasius. 



Family.— LTJCASID.^. 

 Genus. — Lucasius (n. g.) (a M. H. Lucas). 



Telson (cingulum ultimum) coxis obsoletis. Pleopoda posteriora 

 (pedes spurii), duas partes longitudinis telson celata, ad telson marginem 

 exteriorem articulata, basis quadrilateralis. Ischium trigonum nudum, 

 lobns accessorius satis magnus. Appendix crassus. Antenn. extern, 

 terarticulata. Antenn. extern, basis lobatus, filamentum bi-articula- 

 tum ; articuli inter se valde inaequantes. Abdominis cingulum coxae, 

 lmi et 2di absunt, 3tii, 4ti, 5tique satis magna?. Carapacis lobi latera- 

 les magni, lobus frontalis abest. Species una. {Lucasius myrmeco- 

 philus.) 



1. — Lucasius myrmecophilus (Lucas 1 sp.). 



Corpore, toto sub piloso, carapace granulate Fronte arcuato. Telson 

 triangulare subsulcato apice acuto, nitido. Pleopodis posterioribus setis 

 sparsis obsessis. Ischio trigone Appendice accessorio pilis validis 



