STUDIES ON EARTHWORMS. 225 
and Brazil ; showing thus a very wide distribution. Length 
1 decim., breadth 3 mm., it consists of 220 somites. The 
anterior extremity tapers gradually, but there is no prostomium. 
The clitellum occupies somites xtv to xxi. The sete are 
in eight longitudinal rows anteriorly, all the sete being equi- 
distant; but posteriorly they alternate giving sixteen rows. 
The sete themselves are notched at the extremity, which is 
exceptional. The nephridiopores are in a line with the third 
seta counting from the ventral mid-line, but do not follow this 
seta in its displacement in the posterior somites. The male 
pores are in somite xx, and the sete of this somite are trans- 
versely ridged. The spermathecal pores are on the anterior 
edges of somites Vil, VIII, Ix, in a line with the nephridiopore. 
There is only a single pair of seminal reservoirs in somite 
x11. In the posterior region of the body there is a pair of 
peculiar “ pyriform sacs,” of unknown significance, in each 
somite, opening to the exterior between the nerve cord and 
seta 1; the nephridia are also present in these somites. 
The following are the new species of Pericheta, described by 
Perrier. I shall divide these into two groups according to the 
presence or absence of papillz, on the somite xvii, or on the 
neighbouring somites, or in relation to the spermathece. Each 
of these groups may then be subdivided according to the 
number of spermathecee ; and probably some further subdivision 
may be made in reference to the simple or complex structure 
of this organ. The arrangement of the species of this genus 
must be left till more have been studied. I have several species 
at present ready for description, and I will give a more detailed 
synopsis of the species in a future paper. 
I. Perichetz without papille. 
a. With one pair of spermathece. 
6. With more than two pairs. 
II. Perichetz with papillz. 
a. With two pairs of spermathece. 
6. With more than two pairs. 
