786 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
e. Crustacea. 
Minute Structure of Gills of Palaemonetes varians.* — Mr. E. J. 
Allen points out that the main venous channels in the gill of this 
Crustacean have the cells which form their walls interrupted at various 
points ; the intercellular spaces which are left are in direct communica- 
tion with the blood-channels, and are filled with blood. The statement, 
therefore, that the circulatory system of Decapods is everywhere closed 
does not appear to be true. It was in the masses of cells surrounding 
the venous channels that Kowalevsky found the litmus deposited a few 
hours after injection, and it seems fairly certain that these cells exercise 
an excretory function. 
In addition to these excretory cells a large number of glandular 
bodies occur in the axis of the gill. These glands, which are spherical 
in shape, are composed of large conical cells ; some have the body staining 
deeply, others only faintly, and they may be distinguished as the reti- 
culate and the clear glands. This appears to be the first time that 
glandular bodies have been observed in the gills of Crustacea, though 
Braun has observed similar structures in other parts of the body of 
various Decapoda, and P. Mayer and Claus have described glands in 
the Phronimidae which may be looked upon as a stage of those in Palee- 
monetes. 
Stridulating Apparatus of Red Ocypode Crab.f — Dr. A. Alcock 
suggests that the sound made by the red Ocypode Crab that swarms on 
all the sandy shores of India may be used as a warning note to others 
of its kind which are flying from enemies that the burrow to which they 
are retreating is already occupied. It is true that this crab is gregarious, 
but it does not appear to be social, and we must, therefore, look for 
an explanation of the phenomenon in something that is useful to the 
individual. 
Deep-Sea Paguridse.lf — MM. A. Milne-Edwards and E. L. Bouvier 
have a preliminary report on the Paguridse collected during the expe- 
ditions of the 4 Travailleur ’ and the ‘ Talisman,’ as well as on those col- 
lected by some less notable expeditions. Of the forty-four species collected 
twenty- three are new, and of the twelve genera represented three are 
new. Attention is drawn to the extraordinary plasticity of the Paguridae ; 
while Anapagurus and Catapagurus and others have only one sexual 
tube (which itself varies greatly in form and position), Nematopa gurus 
and Catapaguroides have two, the right of which is always much 
more developed than the left. A progressive disappearance of some of 
the appendages may be seen in Sympagurus ; there may be remarkable 
variations in the number and development of these paired appendages ; 
and proof is afforded of the weakness of the artificial barrier set between 
Sympagurus and Parapagurus and based on the form and number of the 
branchial elements. 
Cancellus , a true Pagurid, has at first a close resemblance to the 
macrurous Pylocheles. A very valuable portion of the collection consists 
* Quart. Journ. Micr. Sci., xxxiv. pp. 75-84 (1 pi.). 
t ‘ Administration Report of Marine Survey of India for 1891-2.’ See Ann. and 
Mag. Nat. Hist., x. (1892) pp. 336 and 7. 
x Ann. Sci. Nat., xiii. (1892) pp. 184-226. 
