THE GENERA OF NEMËRTEANS. 2119 



There are no longitudiual dark streaks on the head , nor 

 could I discern any eyes. 



23. Cerehratulus fuscus (Mac Intosh) Hubr. 

 Synon. Micrura fusca Mac Intosh. 



The representatives of this species in Naples do not 

 seem to attain a considerable length. They generally mea- 

 sured from 3 to 5 cm. On the yellow ground-colour the 

 minute brown dots and specks are much more numerous 

 and better visible than would appear from Mac Intosh's 

 figure. A caudal appendage is present. 



24. Cerehratulus aurantiacus (Grube) Hubr. 

 Synon. Meckelia aurantiaca Grube. 



Micrura aurantiaca Mac Intosh. 

 Cerehratulus croceus Grube. 



Bright orange with a white transverse band behind the 

 tip of the snout. No specimens were examined exceeding 

 7 cm. in length. Tip of the snout truncated as in Cere- 

 hratulus purpureus Urticating elements observed in the pro- 

 boscis, which only measured from 0.007 to 0.009 mm. 

 (exclusive of thread). 



25. Cerehratulus lacteus (Grube) Hubr. 

 Synon. Nemertes lactea Grube. 



» » Ulianin. 



White or yellow , generally with curious transverse 

 wrinkles , which give the animal a different aspect from 

 other Nemerteans. The pigment of the integument becomes 

 detached very easily and then takes the appearance (under 

 the microscope) of feathered stripes. A caudal appendage 

 is present. The eyes which were noticed by Grube seem 

 to be absent in the majority ; I saw them only in a couple 



Notes from the Leyden ]Mu.seuiM, 



