482 Dr. Jff. Woodward — On a New Carboniferous Eurypterus. 



this I believe to be owing to an unfortunate series of fractures, wbich 

 intersect the middle of the carapace just where in other specimens 

 these organs are usually situated. There is a distinct and rather 

 wide and smooth margin to the head-shield, which can be traced 

 for about three-fourths of its circumference, but it is broken away 

 upon the right side by the protruding appendages. 



Three almost entire jointed appendages, furnished with numerous 

 spines at their articulations and with smaller spinelets along their 

 edges, are preserved in situ on the right side of the head. A portion 

 of a fourth is seen on the right anterior border of the carapace ; and 

 portions of the corresponding limbs are shown on the left side of the 

 head. The appendages where best preserved show six articulations, 

 the 1st or coxal joint (making 7 articuli) being hidden beneath the 

 carapace. The two body-segments which follow next after the 

 head-shield are unusually large, being one-third as deep as they are 

 broad, and very strongly squamose, the squamae lying very close to 

 one another and becoming more elongated near the mai'gins of the 

 segments ; the posterior angles of each segment were slightly 

 produced, the points being directed backwards. Portions of five 

 other segments following the 1st and 2nd are seen in place on the 

 right side of the specimen, three of which are also partly preserved 

 on the left side. 



These show that the 3rd, 4th, 5th, 6th, and 7th segments were 

 much narrower than the preceding two, their depth being only one- 

 seventh of their breadth ; the surface-ornamentation too i;ndergoes a 

 considerable change, being sparingly covered with small irregular 

 tubercles. 



Scattered ii-regularly over the somites may be seen a number of 

 small circular disc-like bodies, having a radiating fibrous structure, 

 which I at first mistook for some small polyzoon or other minute 

 sessile parasite, fixed to the surface of the Crustacean. A more 

 careful investigation — in which Dr. G. J. Hinde was so kind as to 

 give me his valuable assistance — showed me that these bodies were 

 actually enclosed within the chitinous substance of the terga, and 

 are in fact deposits of calcite forming part of the crust of the 

 segments themselves. 



Under the description of AntJirapalcemon Parhi (Peach), from the 

 Carboniferous series of Langholm, Dumfriesshire, Mr. B. N. Peach 

 writes as follows^ : — 



"The test is very thin, and probably contained very little calcium 

 carbonate, as it is apt to be filled with calculi,^ such as that now 

 found in the common shrimp. Where the test is thin these are 

 mere scales ; but in the spines and thickened portions they are 

 semi-globular, the rounded part being mammilated. In every case, 

 however, they have a central nucleus from which radiations proceed. 



* See Trans. Eoy. Soc. Edinburgh, 1880, vol. xxx. pt. 1, p. 80 ; see pi. ix. figs. 

 4ff, U. 



^ " Globular calcite." Prof. Huxley informs me that be has noticed this deposit 

 as constantly present within the chitinous test of every Faleemon and Crangon which 

 he has examined. — H.W. 



