en 
5 
of the various species of this genus that SEMPER'S species cannot possibly be included in 
the same. Nor for a like reason can it be grouped with the known species of Dama- 
yantia, Ibycus or Parmarion, to all of which genera it has at various times 
been thought to be related, and althoush at first sicht it micht seem to find its natural 
fe) 
position in the genus Philippinella, a comparison of figures 12 and 15 shows that 
anatomically the differences are too great to permit its inclusion therein. 
I have reproduced (Pl. VIII, fig. 1O—11) SEMPER’s original figures, and that showing 
the dorsal side of the animal (fig. 11) might at first sight be thought to approach 
Philippinella, but a reference to the lateral view (fig. 10) gives one a very different 
impression. Apart from the differences in the external form, the internal structure shows 
a slug much more closely allied to Parmarion than Philippinella. It is suffieiently 
distinet, however, judging from SEMPER’s drawings to be separated from the former genus, 
I therefore propose a new genus — Parmuneulus — for its retention. 
It is curious that this species has never been met with since 1570, and were it not 
that the figures of the generative organs are so different from all other described species 
of Mariaella, l should not hesitate to class it in that genus. ] have in my collection 
young examples of Mariella dussumieri, which resemble SEMPER’s species, as figured 
(Pl. VIIL, figs. 1O—11) very closely. 
The Svystematie Position of Philippinella and Parmunculus. 
[7 PEF 
I] have endeavoured to set forth in tabular form the position of these two genera 
and their relations to other genera which may be considered to have arisen from 
Parmarion-like molluses. 
Parmunculus is undoubtedly closely related to Parmarion, judging from 
SEMPER’S figures while Philippinella is much further removed, it shows a number of 
characters connecting it with this former genus. SIMROTH (4) has drawn attention to an 
interesting point in the anatomy of Mieroparmarion, on page 109 op. cit. he writes: 
„Das starke Septum, welches nur eine enge Communication zwischen dem Fusssaum und 
dem Intestinalsack zulässt, scheint auf engmündige Gehäuseschnecken als Vorfahren hinzu- 
weisen. Der Befund am jüngsten Microparmarion Strubelli (s. o.) scheint solches zu 
bestätigen und die Stammform näher zu umgrenzen. Sie wird eine flache, gekielte Schale 
getragen haben. Dieser Kiel findet noch seinen Ausdruck in der Mantelkante. Man hat 
also für die Ableitung vermuthlich an Gehäuseschnecken von der Form mancher Naninen 
oder der Trochovitrinen zu denken, welche unter dem Einfluss besonders hoher tropischer 
Feuchtigkeit zu stärkerer Herausbildung der Mantellappen und zur Resorption der unter- 
halb des Kieles gelegenen Kalkpartien der Schale gebracht wurden.“ 
This same feature obtains in a lesser degree in all the three species of Philip- 
pinella mentioned in this paper, and to a still smaller extent in Mariaella. 
