370 ^^^ Philippine Journal of Science leis 



follows: Somites I and II consist of 1 annulus each; III and IV 

 of 2 annuli each ; V and VI of 3 annuli each ; VII of 4 ; VIII to 

 XXIII of 5 annuli each ; and XXIV, XXV, and XXVI of 2 annuli 

 each ; making a total of 102 annuli. 



The most prominent features of the ventral surface are the 

 genital orifices, the male opening lying between the 30th and 

 31st annuli of somite X and the female between the 35th 

 and 36th annuli of somite XI, The 17 pairs of nephridial 

 pores are also distinctly visible. The first pair is in the post- 

 erior edge of the 13th annulus, somite VII, and the last in the 

 93d annulus, somite XXIII. In each somite the openings are on 

 the annulus just in front of the one bearing the sensory papillae, 

 which is the second annulus of the somite in every case except 

 somite VII, in which there is only 1 annulus in front of the" 

 papillse-bearing annulus. 



The anus lies in the last, or 102d, annulus. 



The structure and arrangement of the maxillae and the in- 

 ternal organs is much the same as is found generally in the genus 

 Hirudo. 



The color and markings in this species are very constant in all 

 the specimens which have been examined. On the dorsal sur- 

 face the ground color is olive green mixed with a little yellow. 

 Mid-dorsally there is a longitudinal line of a darker green from 2 

 to 4 mm. wide. Running parallel to this line on each side are 

 4 narrow black lines. The margins bear an orange stripe about 

 1 mm. wide. Lying along the dorsal edge of this marginal stripe 

 is a row of deep-green squares, one lying on each third annulus. 

 Ventrally the color is a uniform dark olive green with a velvety 

 appearance. The acetabulum is the same color as the rest of the 

 body. 



The number of annuli and their somite arrangement, the num- 

 ber and position of the eyes and sensory papillae, the number and 

 position of the nephridia, the position of the genital openings, 

 and the structure of the maxilla place this leech in the genus 

 Hirudo. The peculiar papulation of the skin, the prominence 

 of the sensory papillae both on the body and on the acetabulum, 

 the union of the 6th and 7th annuli on the ventral surface, and 

 the distinctive color marking stamp it as a new species. The 

 species is named in honor of Dr. W. H. Boynton of the Bureau of 

 Agriculture of the Government of the Philippine Islands, who 

 has been studying it with reference to its ability to hold the virus 

 of rinderpest alive in ingested blood, and to whom I am indebted 

 for first calling my attention to the species. 



