76 Journal of Entomology and Zoology 



Summary 



1. Trithyreus has no sense organs but sensory hairs, so far as 

 could be determined. 



2. The central nervous system resembles that of a spider quite 

 closely, but the thoracic ganglion is more elongate and there is an 

 abdominal ganglion. 



3. The brain is complicated, but few long tracts of fibers are 



evident. 



4. There may be areas which may represent anterior and poste- 

 rior pairs of globuli of spiders and scorpions, but if so they do not 

 have the same structure. 



5. There are no trachea in the central nervous system. 



6. The cells are uniform except for a mass each side of the 

 brain in a cephalic dorsal position. 



7. This dorso-lateral group of cells strongly suggests a special 

 higher center. Longer fibers were seen in connection with it than 

 with any other part. 



REFERENCES 



Beitrage zur Morphologic der Arthropoden. Zoologica. Heft 42. 



Borner, L. 



Cook.O.F. 1899 



"Hubbardia": A new geni.s of Pedipalp!. Proc. Wash. Ent. Soc. 

 Vol. IV. 

 Haller,B. . 1912 



Uber das Zentralnervensystem des Skorpions und der Spinnen. 

 Archiv f. Mic. Anat. Bd, 79. Abt. I. 

 (Contribution from the Zoological Laboratory of Pomona College) 



