ANATOMY AND GENERIC CHARACTERS OF SCORPIONS. 373 



means of injections, an exploration of the great veins of the Scorpions. My observations 



were made upon freshly-killed specimens oi Andrortonus funestus, which I obtained from 



North Africa for the purpose. I used as injecting material sometimes soluble Berlin 



blue, sometimes a mixture of wax, tallow, and turpentine coloured by vermilion. By 



introducing the injection at various points, especially into the venous sacs surrounding 



the lungs (by means of a very fine nozzle) I satisfied myself that there is no passage 



through the pericardio-ventral muscles to the pericardium. The chief veins leading 



from these dilatations of the ventral blood-sinus to the heart run up the sides of the 



body quite superficially, lying outside the longitudinal dorsal muscles between these and 



the integument. They enter the pericardium at its dorso-lateral angles right and left 



(PI. LXXXI. figs. 1 & 2, svsl). Deeper than the longitudinal dorsal muscles is a 



second series of veins parallel to the first ; but these do not open into the pericardium. 



In a pale-coloured Androctoims, the position of the main venous trunks may be seen 



by transparency when they are injected either from the pericardium or from one of the 



circumpulmonary sinuses. Views of a specimen thus injected are given in PI. LXXX. 



figs. 1, 2, 3. On the ventral surface (fig. 3), the injection shows at intervals near the 



mid-line, and the edge of the circumpulmonary sinuses are also seen. Internally it is 



found, on dissection, that the injection, besides occupying numerous large flattened 



spaces between the lobes of the gastric glands and the genital organs, is chiefly 



aggregated in two deep-lying latero-ventral longitudinal trunks which dilate around 



and enclose each in-pushed lung-book. Although the pericardium also is found to 



be full of the injection and the hollow pericardio-ventral muscles are half-filled (on 



their pulmonary side) with injection, yet no injection is found to have penetrated along 



the whole length of these muscles so as to reach through to the pericardium. 



On the contrary, the veins connecting the pericardium and ventral longitudinal sinuses 

 are seen when a lateral view of the specimen is taken (fig. 2) to be injected. Here we 

 find a large vein (svsl) branching in the prosomatic carapace, returning some blood from 

 the coxal glands and the limbs. In the first and second mesosomatic segments small veins 

 {svsl^, svsl-) are seen bringing the blood from the genital and pectinigerous segments 

 to the pericardium. In the third, fourth, fifth, and sixth mesosomatic segments these 

 lateral veins are much larger and extend directly from the circumpulmonary venous 

 sacs to the pericardium. They appear also to have wide anastomatic trunks running 

 longitudinally between them. In the first metasomatic segment, the lateral veins 

 have a strongly marked posterior direction, and do not reach the ventral surface. 



The arterial system of Scorpions (probably of Aadroctonus) was carefully described 

 by Newport ; but he was not able to give a decisive account of either the capillary or 

 venous system, on account of the fact that his specimens were not living, but badly 

 preserved in spirits. 



In PL LXXX. fig. 15, I have drawn a view from the inside of an actual dissection 

 displaying the tergum and large vessels, pericardium and muscles of Aridroctonus 



