64 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
ness, Itrests upon a mass of connective tissue (c.)-much thicker than that form- 
ing the base of the larger organs, being in fact thicker than the lenticular mass 
itself. Above it is a similar layer of connective tissue (cl.) with thickly dis- 
tributed nuclei very similar to that described above. The radiating fibrils 
(f.) in this case seem to spring directly from the connective tissue itself with- 
out any intervening structureless mass. They are thicker, shorter, and more 
closely packed than in the larger organs, and as they do not thin out towards 
their extremities there is no clear zone produced on the outer surface, 
These smaller organs, too, appear to be much more brittle than the larger 
ones, for only in very few cases have I found their sections at all complete, 
The only organs which at all approach the pallial organs just described are 
to be found in the somewhat closely allied species Abralia oweni, which 
has been the subject of a memoir by Professor Joubin (95). In common 
with the form under consideration they are of a spheroidal shape and are 
surrounded in their deeper half by sacs of pigment which may be modified 
chromatophores. The network of vessels described and figured by Joubin 
(p. 11 [222], Fig. 6) appears to be replaced by the lacunae above mentioned. 
Here, however, the resemblance ceases ; it is only with difficulty that the 
internal structures can be regarded as in any way homologous with each 
other. 
Judging by composition alone, it might be said that the crystalline style 
(tige cristalline) of Joubin is represented by the funnel-like apparatus of 
Abraliopsis, but even here differences obtain, for whilst the style occupies the 
very centre of the organ, the funnel is hollow and in its middle is found a 
cellular plug. Furthermore, the style is described as consisting of concentric 
layers and quite devoid of nuclei, whereas the funnel is made up of rodlike 
elements, arranged around a centre, it is true, and nuclei, though in small 
numbers, are present. 
There is nothing, apparently, in the organs of Abralia corresponding either 
to the lens-like body, to the central cone, or to the hard posterior eup in 
Abraliopsis, whilst on the other hand the latter shows nothing like the hood 
(calotte) or the network (reseau) observed in the former. 
Iu the face of discrepancies such as these in the case of forms which do not 
seem to be far apart systematically, the elucidation of the functions of the dif- 
ferent parts on anatomical or histological grounds seems wellnigh hopeless, 
I am not acquainted with any organs at all resembling those found on the 
eyes of Abraliopsis hoylei. 
