1887]. Zoology. 857 
L Sub-Class Calcarea. 
1, Order Calcispongiæ. : 
i, Sub-Order Homoccela, with the families Asconide, Ho- 
modermidz, and Leucopside. i 
ii, Sub-Order Heteroccela, with the families Syconide, 
= Sylleibidze, Leuconidz, and Teichonidz. 
_ IL Sub-Class Silicea, 
= L Order Hexactinellida. : 
= L Sub-Order Lyssacina, with the families Euplectellide, 
Asconematidz, Rossellidæ, and Hyalonematide. 
ii, Sub-Order Dictyonina, with the families Farreidz, Eure- 
tide, Melittionide, Coscinoporida, Tretodictyide, and 
d 
ie 
eandrospongide. 
2. Order Chondrospongiz. i 
1, Sub-Order Tetraxonia, with the families Rhizomorinide, 
X Anomocladinæ, Tetracladinidæ, Corticidæ, Pachystrel- 
lidæ, Plakinidæ, Oscarellidæ, Geodidæ, Stellettidæ, The- 
_ heide, Tetillidz, and Tethyopsyllide. 
li, Sub-Order Monaxonida, with the families Tethyde, 
Sollasellider, Spirastrellidze, Suberamatidæ, and Suberi- 
idee, 
iii. Sub-Order Oligosilicina, with the families Chondrillide 
and Chondrosidz. 
acuspongie, a 
>ab-rder Halichondrina, containing the families Spon- 
Sillide, Homorhaphidz, Heterorhaphide, Desmacidon- 
.. dz, and Axinellidze, 
ub-Order Keratosa, with the families Spongide, 
Aplysinidar, Hircinide, Spongelide, Aplysillide, and 
Halisarcidæ, 
: The article concludes with a nearly ex- 
n l0graphy of the literature of recent sponges, no less 
test eet hundred and fifty-four titles being enumerated. 
bibliography Previous to this (that of D’Arcy Thompson, 
Contained five hundred and fifty-one titles. In this con- 
lendeng, Student Should consult the errata given by Von 
x ld in the Zool, Anzeiger, No. 254. 
T O 
seven Presen 
È Fall pit Specimens of Unto aberti Conrad, just then collected $ 
E in that State. -One of these specimens proved to ~ 
you i i the ctenidia of which were surcharged with develop- n 
ipe; It was particularly interesting, however, because of oe 
but co of the branchial uteri, which has been hitherto 
~ Once in any species of Unio. ; ae 
the Ctenidium of Unio aberti Conrad.—In January 
t year a gentleman resident in Kansas sent me 
