204 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
and eosinophile blood-corpuscles, and of the basopbile cells of the cell- 
tissue of Astacus. They also all of them may, under appropriate con- 
ditions, ingest solid masses. 
Persistent Nauplius Eye in Decapods.* * * § — Miss M. Robinson bas 
observed the persistent nauplius eye in Palsemon serratus, Virbiua 
varians, and Pandalus annulicornis. On removing the rostrum from a 
fresh specimen the median eye can be seen as a black speck lying in the 
centre of the triangle formed by the brain and the stalks of the lateral 
eyes. The brain is covered by chitin, which is lined by a thin layer of 
ectoderm ; if the dorsal part of this and a small piece of the anterior 
portion of the brain be removed, the eye can be seen lying in a blood- 
space just dorsal to the brain. It has the appearance of a black )( which 
is slung on to the ectoderm by two slender threads which swell out in 
the concavities formed by the arms of the )(, and then narrow again as 
they approximate to each other. 
The )( consists of two large pigment cells and the supporting 
strings are formed partly of ectoderm, and partly of club-shaped nerve- 
end cells. No trace of a refractive body could be found within the eye. 
On the whole the resemblance to the median eye of Branehipus, as 
described by Claus, is very close. This eye has been observed in the 
adults of eight species of Candidas. 
Abnormalities in Astacus fluviatilis.f— Prof. W. N. Parker has a 
notice of three abnormal Crayfishes. In one there was a small but well 
developed pleurobranch on the wall of segment xii. in place of the usual 
rudimentary style ; the normal pleurobranch on segment xiii. was pre- 
sent. In another the last arthrobranch on the left side was forked ; the 
bifurcation began close above the base, and the two branches were nearly 
equal in size. The third specimen exhibited a partial fusion of the 
fourth and fifth abdominal segments ; the calcified sternal bars were 
completely fused from the middle line nearly to the attachment of the 
appendage on the right side. 
New Family of Schizopoda.j: — Prof. P. J. Van Beneden describes a 
new Crustacean from the Azores for which he proposes the name of 
Cryptopus Defrancii, and for which it is necessary to establish the new 
family Cryptopodid®. It appears to be allied to the Isopoda, while its 
Schizopod affinities are most with the Eupliausid®, for, like them, it has 
no marsupium, and exhibits inetamoiqihosis. 
British Species of Fresh-water Cyclopidse and Calanidse.§ — Prof. 
G. S. Brady has published a useful and richly illustrated revision of 
these species, the discrimination of which offers very considerable diffi- 
culties ; in all cases it is necessary to dissect and examine under high 
powers of the Microscope very large numbers of specimens. 
* Quart. Journ. Micr. Sci., xxxiii. (1892) pp 283-7 (1 pi.). 
f Ann. and Mag. Nat. Hist., ix. (1892) pp. 181 2. 
X Bull. Ac. Roy. Belg., lxi. (189i) pp. 444-59 (1 pi.). 
§ Nat. Hist. Trans. Northumb., Durham, and Newc., xi. (1891) pp. 08-120 
(14 pis.). 
