256 W. B. BENHAM. 



Intestinal pouches in Somites xvi to xxv. 



A pair of tubular intestinal caeca in Somite xxvi resembling 

 those of Perichseta. 



All the nephridia have a large csecum ; the duct being very 

 long in the first seven nephridia.] 



Species 1. U. brasiliensis, W. B. B., 1886; Brazil. 

 See Benham, ' Quart. Journ. Micr. Sci./ xxvii. 



Genus 27. Hormogaster, Rosa, 1887. 



Setse in couples; those of the inner couple rather far apart. 



Clitellum occupies Somites xv to xxv. 



Tubercula pubertatis along the edge of the clitellum on 

 Somites xviii to xxiv. 



Spermiducal pores between Somites xv and xvi. 



Nephridiopores in line with Seta 2. 



Sperm-sacs in Somites xi and xii. 



Gizzards three, in Somites vi, vii, viii. 



[Globose intestinal cseca in Somite xxi, and smaller ones 

 in following few somites. 



Spermathecae in Somites x, xi, xii. 



Testes and rosettes in Somites x^ xi. 



Nephridial ducts provided with slight caecal prolongations.] 



Species 1. B. redii, Rosa, 1887 ; Italy. 

 See Rosa, ' Sulla Struttura dello Hormogaster Redii,' Torino, 

 1888. 

 ^ Genus 28. Brachydrilus, Benham,, 1888. 



Setse very small, in four couples. 



Clitellum occupies Somites xvi to xxi (though probably 

 more). 



Spermiducal pores in a deep fossa occupying Somite 



XVIII. 



Two pairs of sperm-sacs, in Somites x, xi, enclosing the 

 ciliated rosettes. 



Large and muscular thickening of body-wall, through which 

 the sperm-ducts pass to the exterior, occupies Somites xv 

 to XX. 



