356 MISS E. J. BECK ON THE MUSCULAR 
The muscles 79, 81, & 83 run between the epimeron and the plastron, the muscle 87 
between the epimeron and the second entochondrite, and the muscle 124 between the 
epimeron and the pectine. 
The anterior dorso-epimeron muscle (126) is attached to the lateral portion of the 
carapace and to the epimeron lateral to the interior margin of the second coxal sclerite. 
The median dorso-epimeron muscle (127) is attached to the lateral portion of the 
carapace and to the epimeron lateral to the interior margin of the third coxal sclerite. 
The posterior dorso-epimeron muscle (128) is attached to the lateral portion of the 
carapace, and to the epimeron lateral to the interior margin of the fourth coxal 
sclerite. 
VIII. Muscles to the Pharynz. (See Plate LX XIX. figs. 11, 12.) 
The pharynx of the Scorpion is a large dilatation of the alimentary canal closely 
following the aperture of the mouth. This aperture is so minute that the animal lives 
entirely on the juices of its prey, and on the hard parts finely pulverized by the action of 
the chelicere: these juices are drawn in at the oral aperture by the expansion and 
contraction of the pharynx. On contracting the muscles form within the pharynx 
a partial vacuum; and as the aperture of the csophagus on leaving the pharynx 
is smaller than that of the mouth, the vacuum is more readily filled from the latter. 
The muscles attached to the pharynx are of two kinds, the extrinsic, which dilate, 
and the intrinsic, which contract it. It is thus rendered a powerful suctorial organ. 
In transverse section it is shown to be very narrow, the lateral walls almost meeting ; 
its dorsal portion is curved downwards, and forms a lateral groove, which gives it a 
triradiate form. 
The dorsal intrinsic muscle (129) consists of three small bands of muscle which 
are attached to the dorsal surface of the pharynx within, and to the walls on either 
side of the groove. This muscle is so small that it is only by means of sections that 
it is visible; it is, of course, not repeated on either side of the animal, as it is itself in 
the median line. 
The lateral intrinsic muscle (130) runs closely by the lateral walls of the pharynx, 
and is attached dorsally and ventrally to its walls. This muscle cannot be seen without 
the aid of sections. 
The anterior preoral entosclerite pharyngeal muscle (98) (Pl. LX-XIX. fig. 12) is a 
small muscle attached to the ventral surface of the anterior portion of the preoral 
entosclerite. It runs down almost vertically into the groove on the dorsal surface of 
the pharynx, to the wall of which it is attached. 
The posterior preoral entosclerite pharyngeal muscle (99) is a larger muscle 
attached to the interior surface of the processes of the preoral entosclerite, and runs 
almost horizontally to the lateral wall of the pharynx, to which it is attached. 
