188 A Leech from Angola 
The crop, which was not fully investigated posteriorly, has paired caeca like 
Hirudo. 
The blood is red. 
The pharynx is long and plicated as in Aulastoma, Moquin Tandon. In the 
largest specimen these plications or folds are indistinct; in the second specimen 
twelve, equal, longitudinal plications were clearly seen. 
The ventral side of the anterior sucker is bounded anteriorly by a deeply 
wrinkled lip with an inner crenulate border. From a median point slightly behind 
this border, two ridges diverge posteriorly, dividing the hollow, ventral surface of the 
sucker into three depressions and forming a triangle with the edge of the mouth, 
which appears as a transverse ridge in individuals laid open by a median, ventral 
incision as shown in Fig. 5. The depressions within and without this triangle vary 
considerably in form according to the amount of stretching to which the individual 
is subjected, a fact which may account, to some extent, for the conflicting descrip¬ 
tions of similar features in other leeches. 
The ridge formed by the edge of the mouth is extended posteriorly into a frilled 
membrane overhanging the ends of the pharyngeal plications and beneath it the 
maxillae, if present, should be found. 
Although the above diagnostic characters are not complete, it is 
evident that Dr Wellman’s leech is one of the Gnathobdellidae, a group 
which Dr R. Blanchard divides into the two sub-families Hirudininae 
and Haemadipsinae. 
The presence of a ring between the third and fourth pairs of eyes is 
sufficient to separate this leech from the Haemadipsinae or true land 
leeches, and it therefore must be placed in the first sub-family. 
The same authority assigns to the Hirudininae the following genera, 
viz., Hirudo, Haemopis [= Aulastoma, Moquin Tandon], Limnatis, 
Hirudinaria, Macrobdella, Whitmania and Limnobdella. 
This leech differs, amongst other characters, from Hirudo in the 
absence of the three powerful jaws ; from Haemopis [= Aidastoma, M.T.] 
in the form of the crop; from Hirudinaria and Macrobdella iu the 
number of rings separating the genital apertures. Iam unable to speak 
positively with regard to Limnobdella and Whitmania as I have been 
unable to analyse somites VI and XXIII owing to the absence of 
segmental papillae. Taking everything into consideration I venture to 
place Dr Wellman’s leech in the genus Limnatis which it appears to 
resemble most closely. In particular, Dr Blanchard’s description of the 
anterior sucker of Limnatis as “creusbe d’un sillon en dessous” and 
Moquin-Tandon’s description of the same as “ profondement creusee en 
dessous d’un canal en triangle ” seem to agree with the characters shown 
in Fig. 5. 
