THE CHAETOGNATHA OF THE SIBOGA EXPEDITION 



WITH A DISCUSSION OF THE SYNONYMY AND DISTRIBUTION OF THE GROUP 



BY 



G. HERBERT FOWLER, B.A., Ph.D. 



With 3 plates and 6 charts. 



I. Introduction. 



a. THE MATERIAL COLLECTED, AND ITS PRESERVATION. 



The material received, amounting to thousands of specimens, was contained in a 

 few tubes of most beautifully preserved specimens in Formalin, and in a large number of tubes 

 of alcoholic specimens very much less well preserved. To have identified every specimen with 

 accuracy would have required years of close application, and the results which might have 

 been expected from this procedure would, apparently, not have been commensurate with the 

 labour involved. 



The Formalin specimens were therefore studied first of all with considerable care, 

 until the species represented in this material were thoroughly familiar ; afterwards a good deal 

 of the determination was done under a dissecting lens ; and only doubtful or unfamiliar speci- 

 mens were put under the microscope, measured, and counted. 



Had not the formalin material been available, and been carefully studied, the determina- 

 tion of the Alcohol material would have been in most cases almost impossible ; the fins 

 and corona ciliata had generally entirely disappeared, the body had become shrunken and 

 distorted, thus giving a disproportionately large appearance to the head, and the opacity of the 

 tissues made the counting of the teeth both difficult and uncertain. Except in the case of a 



SIBOGA-EXPEDITIE XXI. I 



