58 Dr. Anton Fritsch — On Prolimulus Woochcardi 



The body consists of two rounded shields, with thickened margins 

 measuring 13 mm., the telson is 14 mm. in length, the whole length 

 of the specimen being 27 mm. 



Diagrammatic sketch of Frolimuliis Woodwardi, Fritsch, enlarged four times. 



The dorsal surface is generally covered with, some calcareous 

 coiled discoidal tubes of Spiroglyphus vorax, Fr. On the ventral 

 part of the cephalothorax (if made wet with gum-arabic) five pairs 

 of extremities can be detected, the first being very stronglj' curved 

 inwards, the fifth long and slender, being supported by a sternal 

 element. 



On the ventral surface of the abdomen we can see rounded plates, 

 probably the modified abdominal appendages covering the respiratory 

 organs, or branchise. The telson is inserted in an invagination of the 

 hinder margin of the abdomen. 



I hope that the galvanoplastic casts which I have had prepared of 

 some of the developed natural impressions will help us to recognize 

 more of the details of the structui-e of this Permo-Carboniferous 

 king-crab. Prolimulus very closely resembles one of the embryonic 

 stages of the living North American Limuliis polyphcemus. 



