ANATOMY AND GENERIC CHARACTERS OF SCORPIONS. 383 
of the mouth. For the muscles referred to by numbers, see the list on 
p- 359. 
Fig. 15. View from below of the pericardium, arteries, pericardio-ventral (veno-peri- 
cardiac) muscles, and dorso-ventral muscles of Androctonus occitanus. 
Magnified two diameters, and drawn from an actual dissection. 
pp'—pp’, the series of pericardio-ventral muscles running from the peri- 
cardium to the wall of the great ventral vein or sinus of the same side; 
ar\—ar®, the lateral arteries of the mesosoma ; a7’, the lateral artery of the 
first metasomatic segment; dv'!—dv®, the six dorso-ventral muscles of the 
mesosoma; dv, the dorso-ventral muscle of the first metasomatic segment. 
PLATE LXXXI. 
Figs. 1 and 2. Transverse sections of the mesosoma of Scorpio italicus, to show the 
venous blood-spaces and the pericardio-ventral muscles. 
alax, axial portion of the alimentary canal; a/c, glandular cca of the 
alimentary canal; cc, coagulum within the heart; cv, valve and aperture of 
the heart-wall; cog, coagulum in the pericardial blood-space; cpb, fibrous 
bands from heart-wall to pexicardium (ventral) ; cpu, similar dorsal bands ; 
cw, heart-wall ; dvs, deep latero-dorsal vein or blood-sinus; sus, superficial 
latero-dorsal vein (same as marked svs/** in Pl. LXXX. fig. 1); ge, 
genital follicles (testis) ; /b, lamelle of lung-book; Jum, longitudinal ventral 
muscle ; /g, ventral insertion of dorso-ventral muscle; ddm, dorsal longi- 
tudinal musculature ; », nerve-cord ; pus, pericardial blood-space ; ppm (in 
fig. 2), the pericardio-ventral or pericardio-pulmonary or veno-pericardiac 
muscles passing from the pericardium to the roof of the circumpulmonary 
blood-sac ; ps, the circumpulmonary blood-sac; spa, supramedullary artery 
of Newport. 
Figs. 3 and 4. Transverse sections of the lamelle of the lung-books of Androctonus 
funestus, showing the blood-spaces, B, containing blood-corpuscles, dc, and 
traversed by short cell-columns, cc (as in Limulus), and the air-spaces, A, on 
the lining of which the cuticle is roughened (ornate). 
In fig. 3 the drawing is inverted since the points yy are the free ends of 
lamelle, which stand upwards into the blood-space, the spaces between these 
air-holding lamelle being open to the blood-current. 
In fig. 4 the section passes through a region where the ends of the air- 
holding lamelle are fused to the wall of the cireumpulmonary blood-sinus 
and to one another by the tissue 2. 
Fig. 5. Reticular ornament from the air-bathed surface of a lung-lamella of Androctonus 
funestus, near the centre of the lamella. 
VOL. XI.—ParT x. No. 10.— May, 1885. 3 L 
