W. A. Harding 
167 
Aulastomum gulo, Rhode, 1891, p. 1 et seq. (nervous system) ; Retzius, 1891, p. 1 el 
seq. (nervous system) ; Leuckart, 1894, p. 617, fig. 264 (pharynx). 
Diagnosis. Body soft and flaccid, flattened, attenuated anteriorly, 
bluntly rounded posteriorly, the sides more or less parallel from the 
clitellum to somite XXIII. It is less contractile than Hirudo medici- 
nalis and incapable of assuming the form of an olive. Very young 
individuals are grayish, finely speckled above and below with black and 
bear upon the dorsal surface a geometrical pattern of which the most 
Fig. 11. Haemopis sanguisuga. Diagram of anterior and posterior extremities. 
Somites numbered in Roman numerals, rings in figures. The 5 pairs of eyes are 
indicated by black dots. 1st pr. neph., 17 th pr. neph., position (on ventral surface) 
of first and seventeenth pairs of nephridiopores. an. Anus. (Adapted from 
Whitman.) 
11—2 
