482 AUSTRALIAN HIRUDINEA, III., 



The eyes occupy the positions characteristic of the genera 

 Hirudo and Lim7iobdella, namely, on annuli 1, 2, 3, 5, and 8. 



There are present no sensory papillae on the surface, as in //. 

 medicinalis, so that, beyond the assistance given by the five pairs 

 of eyes at the anterior extremity, one has to rely on the nephri- 

 diopores and nerve-ganglia. By passing fine needles through these 

 ganglia and the ventral body-wall, I was enabled to make out 

 definitely the relationship of the nerve-ganglia to somite-extent 

 and constitution. 



The lower lip is formed by annuli 5 and 6, which, as mentioned 

 above, are fused on the ventral aspect. A similar state of aff'airs 

 obtains in the case of Hirudo mauimia. 



The genital apertures occur in the usual position for members 

 of the genera Hirudo and Limnohdella. The male aperture is to 

 be seen, as a prominent slit, on the 30th annulus, at about the 

 anterior limit of its posterior third. Counting the postoral 

 annuli, it is observed to lie on the apparent 24th annulus seen on 

 the ventral side, but this is, in reality, the 26th postoral annulus, 

 owing to the fusion ventrally of annuli 5,6, and 7,8 respectively. 

 Evidently the annuli are similarly fused in the case of H. mauianay 

 as Benham states that the male aperture lies on annulus 30, or 

 on the posterior limits of the 24th postoral annulus, annuli 5 and 

 6 being fused to form the lower lip. Such could not be the case 

 were two other annuli not also fused ventrally, and these, in 

 all probability, are annuli 7 and 8, what he calls the 24th post- 

 oral annuli being, in reality, the 26th postoral annulus. This is 

 another point of agreement externally between H. mauiana and 

 L. australis. 



The female genital pore lies between annuli 35 and 36, that is 

 postoral annuli 31 and 32, or, counting only the annuli which 

 can be made out on the ventral surface, the 29th and 30th 

 apparent postoral annuli. 



The jaws are crescentic in outline in their teeth-bearing portion. 

 The teeth are 48-50 in number, and are very long and strong. 

 Their number and nature are excellently described in the portion 

 of Blanchard's diagnosis bearing on that subject as " Maxillae 



