200 
PROCEEDINGS OF SOCIETIES. 
twenty-one rings we have more than two primary divisions, viz., four¬ 
teen anterior rings (cephalo-thorax), seven posterior rings (abdomen). In 
some genera and groups we find (as Amphipoda) the first of these split 
up secondarily into two parts, and here it doubtless is convenient to name 
each of the parts. Used in this subordinate sense, the terms head, cepha- 
lon (or what I conceive means the same thing), carapace (as correctly 
used), and pereion, or thorax, may be used. Abdomen and pleon are 
confessedly identical—the only objection to the former term being, that 
it has been used to express an organ among the Yertebrata, an objection 
which, perhaps, after all does not signify much. The appendages of the 
segments, however, much need distinctive names, and there can be no 
objection to those suggested in the Report alluded to. Telson, in the same 
manner, appears to be an organ which is constant in its relations, and a 
most important one, specifically speaking, among the Isopoda. 
I would suggest the following alterations in the sequence of the 
families of Oniscoidea as given in the Analysis:— 
Tylidse, Actsecidse, Porcellionidae, Oniscidse, Philoscidse (Philoscia, 
Scyphax), Philougridse, Titanethidse (Titanethes, Styloniscus, Ligidium), 
Ligidae. 
DESCRIPTION OF PLATE XXIII. 
Fig. 1. Philoiigria rip aria magnified :—1 b, posterior pleopod; 1 /, mi¬ 
croscopic appearance of integument. 
Pig. 2. Phil, vivida: —2 d, posterior pleopod; 2 c, inferior view of an¬ 
tennae ; 1 e and 2 e, internal antenna; 2/, integument. 
Pig. 3. Phil, rosea : —3 b, telson and posterior pleopod; 3 c, inferior view 
of head; 3/, integument. 
Pig. 4. Philoscia Couchii :—4 b, telson and posterior pleopod; 4 d, pos¬ 
terior pleopod. 
The President declared the following gentlemen duly elected:— 
Honorary Member. —Charles Spence Pate, P. L. S., Plymouth. 
Corresponding Member. —James Martin, M. D., Portlaw. 
Associate Member. —Robert Pall, Esq., T. C. D. 
Ordinary Members. —John MTlwaine, Esq., Dublin; M. "Weld 
O’Connor, Esq., Dublin; Robert Samuel Reeves, Esq., Dublin. 
The Meeting then adjourned to the month of June. 
FRIDAY EVENING, JUNE 4, 1858. 
Charles P. Croker, M. D., M. R. I. A., Vice-President, in the Chair. 
The previous Minutes having been read and signed,— 
Mr. J, P. Doyle read the following paper— 
