162 Proceedings of the Royal Physical Society. 
XII. Some Newly-Hatched Specimens and a late Embryo of 
Opisthophthalmus. By Matcotm Lavrig, D.Sc., B.A., 
F.RS.E., F.LS., Professor of Zoology in St Mungo’s 
College, Glasgow. [Plate IV.] 
(Read 19th February 1896.) 
While examining some of the Arachnida in the British 
Museum, my attention was drawn by Mr Pocock to two sets 
of newly-hatched Scorpions, which showed certain pecu- 
liarities of structure. Both lots belonged to the South 
African genus Opisthophthalmus, one being the young of 
O. capensis (Herbst) and the other the young of an undeter- 
mined species. Through the kindness of Dr Giinther and 
Mr Pocock, I was abie to examine some of the specimens 
minutely, and to cut a series of sections through one. 
The peculiarity which strikes one at first sight is the 
presence of two long processes growing from the prosomatic 
region. The more prominent of these arises in front of the 
mouth and projects forward like a proboscis (Figs. 1-5, a). It 
has a length greater than that of the carapace, and is found 
in section to be a tube filled with trabecular tissue, and 
probably also containing blood-vessels. Though arising 
immediately in front of the mouth, it has no connection 
either with the cesophagus or with the powerful sucking 
muscles. The cavity appears to communicate with the 
general body space, but is not easily traced among the 
complex structures of this region. 
The other process arises from the dorsal surface of the 
carapace. In O. capensis (Fig. 3, b) its point of origin is close 
behind, indeed almost between, the median eyes. It is bent 
forward, and lies along the carapace, projecting slightly beyond 
the front margin. In the other species (Fig. 2) the process 
arises about ‘2 mm. behind the eyes, and les directed back- 
wards in a groove in the carapace. It fits so closely into 
this groove that it might easily be overlooked. It is shorter 
(measuring about 1 mm.) in this species than in 0. capensis, 
and does not reach the hind margin of the carapace. This 
