THE ANATOMY OF EPIDELLA SQUAMULA 

 SP. NOV. 



BY HAROLD HEATH 



Assistant Professor of Zoology, Leland Stanford Jr. University. 



CONTENTS. 

 Plates XV-XVI. 



Page. 



I. Introduction 109 



II. External Characters no 



III . The Digesth'e System 113 



IV. The Male REPRODucrnrE System 116 



V. The Female Reproductive System 120 



VI. The Egg-laying Process 122 



VII. Excretory System 123 



VIII. The Nervous System 126 



IX. Visual Organs 130 



Literature Cited 133 



Explanation of Plates 134 



I. Introduction. 



In common w^ith the other members of the genus 

 E-pidella, this new species is an ectoparasite frequently 

 occurring on the Bastard Halibut {Paralichthys califor- 

 niciis), and far less often upon various species of Rock 

 Cod {Sebastodes) in the waters of Montere}^ Bay and vicin- 

 ity. Their usual point of attachment is the under surface 

 of the fish, rarely the gill-cavity, where they congregate in 

 numbers ranging from one to more than a hundred, accord- 

 ing to the size of the host. In form they are thin and leaf- 

 like, unpigmented, but of a light yellow color owing to the 

 yolk-glands which show through the transparent tissues, a 

 characteristic which also enables one to observe in living 

 specimens the various organs of the body and many of the 



[109] May 21, 1902. 



