MORPHOLOGY AND MATHEMATICS. 



875 



with orthogonal and logarithmically interspaced abscissal lines, as -shown in the 

 figure, appears to satisfy the conditions. 



FlG. 18. — Geryon. 



Fig. 19.— Lupa. 



Fig. 20. — Coryst.es. 



FlG. 22. — Scyramathia. 



Fin. 21. — Paralomis. 



Fig. 23. — Chorinns. 



In an interesting series of cases, such as the genus Chorinus, or Scyramathia, and 

 in the spider-crabs generally, we appear to have just the converse of this. While 



