254 W. B. BENHAM. 



or seven pairs of nepliridia are larger than the following 

 ones ; and the duct is simple. The first pair, or extra-buccal 

 pepto-nephridia, opening externally on Somite ii, is parti- 

 cularly large, and lies below the oesophagus. 



Gizzard in vii or viii. 



Typhlosole is a small fold, with a spiral line of origin; 



([Esophageal glands, six or eight pairs, in the next following 

 somites. 



In addition to the dorsal vessel, there is a supra-intestinal 

 trunk below it, from which two or three pairs of large " intes- 

 tinal hearts " go to the sub-intestinal vessel.] 



Species 1. R. paradoxus, E. P., 1872; Venezuela. 



2. R. tenkatei, Horst, 1887; Surinam, 



3. R. gulielmi, F. E. B., 1887; Brit. Guiana. 



4. R. ecuadoriensis, W. B. B., 1889 (MS.); 



Ecuador. 

 See Perrier, 'Nouv. Arch, du Mus. d'Hist. Nat. de Paris,' viii, 

 1872; Beddard (Thamnodrilus), ' Proc. Zool. Soc./ 1887; 

 Horst, 'Notes from Leyden Museum,' ix. 



Genus 25. Microch^ta, F. E. B., 1885. 

 Setse extremely small, in couples. 

 Clitellum occupies ten to twelve somites between x and 



XXV. 



Spermiducal pore on Somite xix or xx. 



Oviducal pore between Somites xii and xiii. 



Nephridiopores very large, in a line with outer setae. 



Sperm-sacs in Somites x and xi, each pair being connected 

 by a median sac in Somites ix and x. 



[Prostomium small. No dorsal pores. 



Testes in Somites ix, x, in special sacs communicating with 

 sperm-sacs. 



Ovary in Somite xii.^ 



' The pcristomium in M. beddardi is provided with setfc, and is therefore 

 homologous with tlie pcristomium + the secoud somite of Lum- 

 bricus, hence the position of the ovary and other structures is typical, 

 although dissection shows them one somite anterior to their real somites. In 



