466 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
The bristles on the back of Smaridia pileifera n. sp. are club-shaped and 
hollow ; it may be that they are simply protective, but there is reason to 
believe that from them a repulsive excretion may exude. In a species 
of TinogliscJirus from a bat, the strong appendages end in two chitinous 
claws between which is a cup viscid internally. Some other peculiarities 
of the appendages are noticed. Herr Karpelles also describes the 
remarkably strong and long jaws of Sciphiodes maxillatus , and gives other 
illustrations of remarkable modifications. 
Embryology of Mites.* — Dr. E. Sicher describes some of the stages 
in the development of Tyroglyphus longior , Pterodectes bilobatus, Freyana 
anatina , Histiostoma iulorum. The first stages were not in any case 
satisfactorily observed, but the history of the appendages was followed. 
The most novel result of Dr. Sicher’s researches is the demonstration of 
the presence of a fourth pair of limb-buds in the earliest stages of 
development. They represent the corresponding pair of appendages, 
and suggest the idea of a “ proto-larva.” 
Brain of Limnlus Polyphemus, f — Prof. A. S. Packard has continued 
his investigation of the brain of the King-Crab. Its most striking 
histological feature is the immense development and singular arrange- 
ment of the convoluted, ruffle-like masses which form the thick layer of 
“ nucleogenous bodies,” which form the cortex of the cerebral and other 
lobes, and which inclose masses of myeloid substance. They appear 
to be simply nuclei, but when they are scattered they are seen to be 
ganglion-cells. Another characteristic of the brain of Limulus, as com- 
pared with all other Arthropods, is the remarkably small number of the 
normal ganglion-cells. The striking differences between the brain of 
Limulus and that of Arachnids are pointed out ; in the adult it is made 
up of three pairs of lobes, the first and uppermost of which are the 
lateral-eye lobes ; below them are the median-eye lobes, and the third 
are the cerebral; these last are very irregular in outline and slender. 
On the whole, however, the brain of Limulus resembles that of Arach- 
nids more than that of Crustacea ; no “ deutocerebrum ” or “ trito- 
cerebrum ” is to be found in it. 
The cerebral differences in addition to the other points of distinction 
appear to the author to warrant the separation of the Podostomata 
(Merostomata and Trilobita) from the Arachnids, although their common 
origin is not to be denied. 
5. Crustacea. 
Arterial System of Crustacea. :f — M. E. L. Bouvier gives an 
account of his investigations into the arterial system of Crustacea. The 
ophthalmic artery, before reaching the anterior edge of the stomach, gives 
off several branches not only in the Brachyura, but also in some of the 
Macrura ; at this edge it forms a more or less marked dilatation which 
is probably homologous with that observed in Amphipoda and Schizo- 
poda. The antennary arteries always supply the eyes as well as the 
ophthalmic arteries, and combine with them in the Brachyura to irrigate 
the rostrum. In those Macrura in which the rostrum is well developed 
* Atti Soc. Ven.-Trent. Sci. Nat., xii. (1891) pp. 1-22 (3 pis.). 
t Zool. Anzeig., xiv. (1891) pp. 129-33. 
* Ann. Sci. Nat., xi. (1891) pp. 197-282 (4 pis.). 
