76 Miscellaneous. 
case of the latter. At the first glance we scarcely hesitate, however, 
to consider this leech as a Glossiphonid, for the regular repetition of 
the segmentary papillze and of the nephridial pores on every third 
annulus clearly indicates that the somite is actually composed of 
three annuli; moreover the number of the annuli only amounts to 
sixty-two, and the intestine bears eight pairs of large lateral ceca, 
of which the last pair is continued for a considerable distance 
backwards. 
On the other hand, our species possesses ten large black eyes, the 
general appearance of which recalls in a striking manner those of the 
genus Hamadipsa, the land-leeches of Malaysia; the first four pairs 
of eyes are still contiguous one with another, owing to the reduction 
of each of the first three somites toa single annulus ; but the fourth 
and the fifth pairs are separated by one annulus, in consequence of 
the reduction of somite iv. to two annuli. In other words, the eyes 
of Hamadipsa are borne by the annuli 1, 2,3, 4, and 7, while those 
of Mesobdella are found upon the annuli 1, 2, 3, 4, and 6*, This 
fact already indicates a great tendency towards tl » shortening of 
the somites. As a matter of fact the somites in. are each com- 
posed of a single annulus; somite ivy. has two annuli; somites v.— 
xxii. possess three annuli each ; somite xxi’. has two annuli; and 
somite xxiy., which is the last, has a singleannulus. A remarkable 
fact is that the coalescence of the body is accentuated to such a 
degree that somites xxv. and xxvi., which are functionally less 
important than those of the anterior extremity, have disappeared 
without leaving the least trace behind them. : 
The apertures of the genital organs occupy their normal situation ; 
the testis opens upon somite x., between the annuli 21 and 22, the 
ovary upon somite xi., between the annuli 25 and 26, 
The segmentary papillz are disposed precisely as in the Hiru- 
dinide ; they form eight longitudinal rows on the dorsal surface, 
and those of the inner lateral row are in a direct line with the eyes 
of the last pair. This character forms a further connexion between 
Mesobdella and the Hirudinide. Lastly, it may be added that our 
species has no proboscis, but possesses three little jaws, situated 
exactly as in the Hirudinide, and each armed with from fifty-five 
to sixty teeth. 
To sum up what has been stated: owing to its ambiguous cha- 
racters Mesobdella brevis connects in a remarkable manner the 
Glossiphonide with the Hirudinide. Among the latter it is nearest 
allied to the Heemadipsine both by its mode of life as well as by 
the arrangement of its eyes; but it is clearly distinguished from 
them, as well as from all the other Hirudinide, by the high degree 
of coalescence attained by its somites. The existence of this inter- 
mediate form shows that the two families which have here been 
considered are derived from a common stock, from which the Glossi- 
phonide have apparently diverged less than the Hirudinidee.— 
Comptes Rendus, t. cxvi. no. 9 (Feb. 27, 1893), pp. 446, 447. 
* The eyes appear to be arranged in the same manner in Cyclobdella 
glabra, Weyenbergh, from the Argentine Republic; but otherwise there 
is no resemblance between this species and Mesobdella. 
