CEPHALOCHORDA. 



I. SYSTEMATIC AND ANATOMICAL ACCOUNT. 



By C. Forster Cooper, B.A., Trinity College, Cambridge. 



(With Plate XVIII. and Text-figures 76—89.) 



II. NOTE ON MERISTIC VARIATION IN THE GROUP. 



By R. C. Punnett, M.A., Felloiv of Gonville and Cams College, and Demonstrator 



of Comparative Anatomy in the University of Cambridge. 



I. SYSTEMATIC AND ANATOMICAL ACCOUNT (By C. Forster Cooper). 



CONTENTS. 



PAGE 



1. ASYMMETRON LUCAYANUM 348 



2. Heteropleuron maldivense n. sp 349 



3. Branchiostomum pelagicum 352 



4. Larvae 354 



5. Distribution 358 



The following is an account of two species of Amphioxus from the Maldive region, one 

 of which, viz. Heteropleuron maldivense, is new and related to H. bassanum. An account is 

 also given of some larvae, the adults of which are uncertain. 



I take this opportunity of thanking Mr Adam Sedgwick for permission to work in his 

 laboratory, and for the great interest he has taken in the work. I am also indebted to 

 Mr J. J. Lister, Major Alcock, Mr R. C. Punnett and Mr Crossland for specimens from other 

 localities in the Indian Ocean. I would also thank Mr A. E. Shipley for the encourage- 

 ment he has at all times shewn me. 



G. 45 



