398 THE POPULAR SCIENCE MONTHLY. 



cephalo-thorax in the Scottish example are chelate, but the palpi are 

 not quite so robust. The walking-limbs, though not so clumpy as in 

 P. nuncius, also terminate in a single claw-like spike. The arrange- 

 ment of the sternum shows a large pentagonal plate (metasternite). 

 against which the wedge-shaped coxae of the fourth pair of walking- 

 limbs abut. The coxae of the third pair bound the pentagonal plate 

 along its upper margins, and meet in the mid-line of the body, where 

 they are firmly united. The coxae of the first two pairs, as well as 

 the bases of the palpi, are drawn aside from the center line of the 

 body, showing that, as in recent scorpions, these alone were con- 

 cerned in manducation, or rather the squeezing out of the juices of 

 the prey ; from the circumstance of these being drawn aside, the 

 medial eyes are seen pressed up through the cuticle of the gullet, 

 and a fleshy labrum (camerostome) appears between the bases of the 

 chilicerae. 



" Behind the pentagonal plate and the coxae of the hindmost limbs 

 there succeeds a space shaped like an inverted V, where the test is 

 thin and wrinkled in the line of the long axis of the body. It is just 

 along this line that the trunk or abdomen most easily separates from 

 the cephalo-thorax in recent scorpions, and it is at once apparent that 

 the trunk in this case is as far separated from the cephalo-thorax as it 

 can well be without being detached. Similar longitudinally wrinkled 

 skin is seen to unite the dorsal and ventral scutes up the whole right 

 side of the trunk. At the interior angle of the inverted V there hangs 

 downward a narrow bifid operculum flanked on each side by the combs, 

 which have each a broad triangular rachis set along its lower edge 

 with the usual tooth-like filaments. The combs almost hide the first 

 of the four ventral sclerites, which bear the breathing apparatus in 

 recent scorpions, notwithstanding which all four of these exhibit on 

 their right side undoubted slit-like stigmata at the usual places. The 

 fifth ventral scute of the trunk suddenly contracts posteriorly, and to 

 its narrow end is articulated a long tail of five joints and a poison- 

 gland with a sting. These joints are all constructed on the same 

 principle as those of recent scorpions, and, as the articular surfaces are 

 more highly faceted on the dorsal than on the ventral aspect (a por- 

 tion of the tail of the specimen lying sidewise allowing of these ob- 

 servations), there can be no doubt that the animal was in the habit of 

 carrying the tail over the head (so to speak), and stinging in the same 

 manner as its recent congeners." These characters are shown in the 

 accompanying illustration (Fig. 2), which is on the same scale as that 

 of the figure of the Swedish example (Fig. 1), viz., about twice the 

 natural size. 



The animal is supposed to have wandered to the sea-shore in search 

 of food, and there been imbedded in marine strata. From the com- 

 pleteness of the remains, it is evident that it can not have been car- 

 ried far out to sea ; the rocks of the formation in which the fossil was 



