418 G. WYNHOFF. 



to the same species, and must therefore have been very much alike in 

 the living state. After preservation, however, the difference was very 

 obvious, the one being rather flattened with lateral margins and the 

 other being circular anteriorly and showing no margins even at the 

 more flattened and weaker posterior part of the body. The colour of 

 the more rounded nemertine was moreover brownish, while the bright 

 yellowish colour of the flattened specimen at once proved it to be a 

 small specimen of Cerehratulus roseus. So I suppose the colour of the 

 other specimen to have been a very faint red or rose. The internal 

 structure, however, makes it quite certain that this specimen must have 

 been an abnormally faint coloured and rather large individual of 

 Micrura aurantiaca. All traces of the original colour or of any 

 markings had disappeared. Eyes are absent. The cutis is as thick as 

 the epithelium. There are no traces of a connective tissue layer 

 separating the cutis from the external longitudinal muscle layer, which 

 is much thicker than the circular or inner longitudinal muscle layer. 

 The latter layer has been very much reduced. The cerebral organs are 

 placed above the lateral nerves. The dorsal part of the dorsal brain 

 lobe is situ.ated laterally to the ventral part ; it ends anteriorly to the 

 cerebral organs. The cephalic slits end where the cerebral canal 

 originates from them. They reach as deep as the brain. The mouth 

 is situated beneath the hinder end of the cerebral organs. 



Geographical distribution : Both coasts of France and the Mediter- 

 ranean. 



3. Micrura purpurea {Dalyell). (Mcintosh. Monogr. PL VII, 

 Fig. 3.) 



Locality : Kather common in dredgings from the Sound ; occasionally 

 a specimen from the Eame-Eddystone and the Mewstone Amphioxus 

 Grounds. 



Colour brown ; head white, with a bright yellow transverse bar ; 

 eyes absent. Length 100-200 mm., breadth 2-3 mm. 



Geographical distribution: Sweden, Great Britain, North coast of 

 France, and Mediterranean. 



4. Micrura Candida, Burger { = Micrura lactea, Hubrecht), (Joubin. 

 Les Nemertiens, T. 2, Fig. 23 bis.) 



Locality: Two specimens from the Mewstone and two from the 

 Mewstone Ledge. 



Perfectly white. Eyes absent. 



Geographical distribution : Channel and Mediterranean. 



Two specimens are known from England, one from Stoke Point near 

 Plymouth, and one from Halfway Kock. 



