



BY E. J. GODDARD. 855 



without external marking that distinguishes some from the rest; 

 number of rings in a complete somite 5-11." 



Had no necessity been found to amend the diagnosis as given 

 by Blanchard, in order to include Orobdella, it would now have 

 been necessary to do so in connection only with the eyes. 



For this new leech I propose the name 



Dineta cylindrica, gen. et sp.nov. 



External characters. — Body cylindrical, without any marked 

 change in diameter in any particular part of the body, beyond a 

 slight attenuation towards the anterior extremity. General 

 appearance not unlike that of Orobdella. Length, in the con- 

 tracted condition, about 25 mm.; breadth, in the contracted 

 condition, about 2 mm. Total number of annuli 115. 



The surface is exceedingly rugose, each annulus being divided 

 up into a series of squarish tubercular areas by grooves running 

 from the anterior to the posterior margin of each. The appear- 

 ance of the surface reminds one of the rugose tubercular nature 

 of an Actiniarian such as Bunodes. The grooves themselves are 

 of relatively insignificant importance beyond that they express 

 the rugosity. A large number of annuli are also superficially 

 marked by a fine groove which runs round them, dividing the 

 tubercular areas so as to give the appearance of a double row of 

 the same in the annulus. This secondary annulation in some 

 cases becomes so well developed in places that it is difficult to 

 decide whether one is dealing with one or two annuli; and in 

 such cases one has to rely on the pentannulate constitution of 

 the somite as seen in longitudinal section, in making an exact 

 count of the number of annuli. On the whole, however, the 

 annulation is well marked by distinct furrows. The tubercular 

 nature of the surface apparently is merely an expression of the 

 rugosity and has nothing to do with a tactile or sensory function. 

 This rugosity is most marked in the posterior half of the body. 

 Perhaps one might most aptly describe the surface, especially in 



