ME. H. M. BERNARD ON THE CHEENETID^. 429 



EXPLANATION OF THE PLATES. 

 Plate XXXI. 



Pig. 1. The ventral abdominal surface of an unclassified Ohisium (macerated 

 in caustic potash), showing the stigmata on the 2nd and 3rd segment?, 

 and a pair of rudimentary stigmata on all the following segments 

 in exactly corresjjonding positions. On the right, except in the anal 

 and penultimate segments, these mdimentary stigmata are seen through 

 the upper cuticle, the skin being folded. The hairs are not all drawn, 

 but are indicated by their round points of insertion on the cuticle. 

 There are no traces of openings of abdominal " spinning " glands. 



Fig. 1 a. One of the chelicerse of the same. 



Fig. 2. Macerated specimen from a bottle labelled Ohisium sylvcUiciim. The 

 stigmata are seen through the coxa of the last pair of legs. The seg- 

 mentation at the anterior end of the abdomen is very difficult to ascer- 

 tain. The hairs or their points of insertion are given only on the left 

 side. The rudimentary stigmata are seen nearer the median line and 

 nearer the middle of the segment than in fig. 1 (on this point cf'J 

 text, p. 422). The lateral membrane in this species is quite different 

 from that represented in fig. 1. It is beset with, minute papillte. 

 The openings of the lateral infoldings corresponding with the dia- 

 phragm or waist of other Arachnids is seen («) just anteriorly to the 

 trochanter of the last pair of legs. 



Fig. 2 a. The chelicerse of the same, showing the fine spinning- ducts {d) and 

 their openings. 



Fig. 3. One of the rudimentary stigmata from fig. 2 ( X 2000). The black 

 dots are fine refractive points in the cuticle. 



Fig. 4. Section through the rostrum, showing the labrum (Z) folded down 

 laterally, with the labium {I) fitting into it. Transverse muscles 

 similar to those shown in the section occur in the labrum of Scorpio 

 and of Araneids. 



Fig. 5. The movable lamellas on the coxa of the pedipalps and the paired 

 (sensory ?) prolongations of the labrum. The form of the labium cau 

 also be seen, reminding one of the median process between the pedi- 

 palps of Phrynus. 



Fig. 6. Diagram of the alimentary canal. Commencing at the rostrum r it 

 swells into the sucking-apparatus ss, passes through the ganglionic 

 mass b, to dilate immediately into a system of diverticula, of which 1 

 and 2 are paired and 3 is median and ventral, o represents the 

 ovary (which is shaded), the paired oviducts of which embrace the 

 median venti-al diverticulum (3) ; md, muscle dissepiments between the 

 secondary diverticula {sd) of the 2nd pair. 



Fig. 7. Section through the abdomen ; sd, secondary diverticulum. The large 

 digesting cells excreting between them streams of crystal-like bodies 

 which look black by transmitted and white by reflected light. These 

 bodies are seen mixing with the contents of the canal. The cells are 

 full of food-globules. /. Layer of peritoneal cells, Bertkau's "fat- 

 body." hg. The loop of the hind gut suspended in the median plane. 



