280 W. B. BENHAM. 



Indeed^ Hormogaster might perhaps be iucluded iu the 

 latter family but for the existence of only two pairs of sperm- 

 sacs. 



PcrioiiycidfD 3bmodi-ilida3 



PericliaitidEe 



_ ~Luml)ricida3 



Typha^Id^ / ^^^^.^^- 



..,,.,. J \ / \ /GeoscolecidsB 



Acantnodrilida3 



Lumbricomorpha minora 



I would here record my thanks to Professor Lankester for 

 his help and advice on many points during the progress of 

 this paper. 



Postscript, April 30th. 



While this paper was in the press, I received from Dr. 

 Michaelsen his recently published memoir^ describing two 

 new species and six new genera from the neighbourhood of 

 Zanzibar. 



The two new species are Trigaster stuhlmanni and T. 

 affinis, which are evidently very closely similar. He suggests, 

 with good reason I think, the removal of Horst's species 

 Acanthodrilus schlegelii, A. biittikoferi, and A. bed- 

 dardi, as well as Rosa's A. scioanus, from the genus under 

 which they have been placed in the present paper to my genus 

 Trigaster (= Benhamia, Mich.), since the male pores are 



' " Beschreibuug d. v. II. Dr. F. Stuhlniaim im Miiudungsgebiet des 

 Sambesi gesainiiiclteu Tcrricoleu," 'Jahrb. d. hamburg. whs. Anstalten/ 

 vii, 1890. 



