A NEW CUTANEOUS PARASITE, THE ENTOZOON FOLLICULORUM. 
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latter situation they are excavated in front to form the pharynx, and behind the 
mouth appear to be continuous for a short extent by means of an isthmus of com- 
munication. When these bodies are examined on the upper surface, a dark globular 
body will be seen to be imbedded in the substance of each near its anterior ex- 
tremity. This globular body is an eye of the simple kind, and is surrounded by a 
circular line representing an orbit. On the middle line the mode of junction of the 
reniform bodies is concealed by the flask-shaped organ, and posteriorly it is to these 
bodies that the oval-shaped pieces of the flask-shaped organ are attached. 
These reniform bodies constitute, as I have before remarked, the essential part of 
the bulk of the head ; they give support to the eyeballs ; they form the pharynx ; 
they afford a point of connection to the maxillae, and by means of the flask-shaped 
cephalic organ, they give attachment also to the superior tentacula. When retracted 
into the cavity of the thorax, these bodies may be very distinctly seen through its 
thin and transparent integument. Besides the movement of retraction within the 
thorax, the head admits of flexion and extension, and of a lateral flexion produced by 
rotation on its own axis. The thorax is the largest and broadest part of the animal ; 
it is flattened upon its ventral surface, convex on its dorsal and lateral surfaces, 
narrower in front than behind, and somewhat larger toward the middle than at either 
extremity. It is composed of four broad and continuous annular segments, which 
are distinguished on the ventral surface of the thorax or breast by four strongly- 
marked transverse lines, and on the dorsal surface by as many broad and shallow 
transverse grooves. These shallow grooves are produced by a convexity of each of 
the segments from before backwards ; they correspond interiorly with the spaces 
between the legs, while the convex portion of each segment is on a line with the 
attachment of the legs. With the ventral surface of each of these segments on each 
side of the breast, the four pairs of legs of the animal are articulated. 
The ventral surface of the thorax is flattened, and the epidermic covering is thicker 
in this situation than on the rest of the body. Running along the middle line of the 
breast, the whole extent of the thorax, is a double line (sternum) formed by two 
ridges which are broken at short distances and are continuous with the four trans- 
verse thoracic lines. The latter also consist of double ridges and run outwards, 
forming the boundary mark between the thoracic segments. The most anterior of 
the transverse ridges commence at the extremity of the median ridge, and pass 
obliquely forwards and outwards at each side to the space between the base of the 
anterior leg and the collar of the neck, forming the anterior boundary of the thorax 
on its ventral aspect. These ridges are slightly curved in their course, the convexity 
being directed forwards, and taken together, give the idea of a bifurcation of the 
median ridge anteriorly. The second pair of ridges pass nearly horizontally out- 
wards to the groove between the first and second pair of legs making a very gentle 
curve, the convexity of which is directed backwards. The third pair of ridges are 
more horizontal in their direction than the preceding, and run to the groove between 
