381) T\(iH SKO0snKI«0 



M 11 X 1 1 1 a: — Kiul joint: The bristles of (his joint, as will be seen Inmi what has been 

 said above, also show an exccodinjily close agrecnicnt with regard to their position with the 

 bristles of the corresponding joint in the sub-family Cj/pridininae. On account of this there 

 can scarcely be any doubt that tliere is real homology present. In this case too I have thought 

 myself justified in using a similar alphabetical notation, based on homologization, for these 

 bristles as for those of the sub- family just mentioned. The group whos(> (three to five) bristles 

 form a transverse row on the outside of this joint are consequently denoted as a-bristles, the 

 group (two) distally-anteriorly = b-bristles, the group (three to five) distally-medially = 

 c-bristles and the remaining bristles, situated postero-distally on this joint ^ d-bristles. 



F i f t li limb: — A\'ith regard to the homologization of the bristles on the second 

 exopodite joint I merely refer to what has been written above in tlie description. 



The classification Remarks: — The five species of this genus that have been described in this work certainly 



form quite a natural classificatory unit. 



One of these forms, Ph. Appellofi, is, however, opposed to the others in some characters, 

 especially by its strongly marked sltell sculpture and its jointed rod-shaped organ. On account 

 of this it seemed convenient to distinguish this species as a representative of a new sub-genus, 

 which has been given the name of Sderoconcha. 



Of the species of this genus dealt with in the literature it is rather certain that three 

 others belong to this sub-genus, viz.: 



Ph. Folini, G. S. Brady, 1871, p. 294, pi. XXVII, figs. 1—5. 

 „ sculpia*, „ „ „ 1898, p. 434, pi. XLIV, figs. 15—20. 

 „ flexUis, „ „ „ 1898, p. 435, pi. XLIV, figs. 1—14, pi. XLV, figs. 15, 16. 



All these three forms are characterized by a very powerful shell sculpture, developed in the 

 form of extensive ridges. At least two of them. Ph. Folini and Ph. flexilis, have, in addition, a 

 jointed rod-shaped organ of the same type as Ph. (Scl.) Appellofi. In Ph. sculpta, unfortunately, 

 this organ is unknown. — It does not seem impossible that another species. Ph. Wyville-Thomsoni, 

 G. S. Brady, 1880, p. 160, pi. XXXVI, fig. 1, a — c, is to be referred to Sderoconcha too. Because 

 of the incomplete description — this species is referred by G. W. MOLLER, 1912, to ,,Cypridinidarum 

 genera dubia et species dubiae" — nothing, however, can be said with certainty about it. 



^Mth regard to the nmtual relations of the other species referred to this genus it is still 

 too early to make any definitive statement; the descriptions are generally, unfortunately, too 

 incomplete. It will probably be necessary — even after distinguishing Pleoschisma and Tetragonodon 

 as special classificatory units, cf. p. 348 above — to carry out a further division; I need only 

 point out here that such aberrant forms as Ph. longiseta Ch. Juday and Ph. lomae Ch. JudaY 

 certainly cannot be retained in this genus. 



Detailed diagnoses of the two following sub-genera may conveniently be postponed 

 tmtil a greater number of species of this genus have been subjected to a closer re-examination. 



* This species is, hesitatingly, identified by G. S. Brady himself, 1898, p. '»35 as Streptoleberis crenulaia, G. S. Brady, 

 1890, p. 515. This identification demands too much, however, from the inexactitude of the two descriptions to be 

 adopted a priori. Of course its correctness is not absolutely impossible!! — It does not seem to me impossible tliat 

 Ph. sculpia and Ph. flexilis are male and female of the same species. 



