504 /• PERCY MOORE. [Vol. X. 



while others are entirely protoplasmic. Voigt's figures of 

 Branchiobdella show this well. 



The clitellar glands are arranged in crowded transverse rows 

 between the circular muscle fibres, which are often displaced 

 and carried inward in a highly developed clitellum. On the 

 dorsal side, particularly of the major annuli, the glands are 

 much crowded and of elongated pyriform shape ; while else- 

 where they are more scattered and globular. 



Two or three pairs of large glandular masses are developed 

 in the pharyngeal region of the head. These are of irregular 

 shape, and occupy the spaces between the radial muscles 

 around the pharynx ; the halves of each pair almost touch dor- 

 sally, and extend laterally and ventrally nearly to the nerve 

 ganglia, while the several pairs are separated by strong muscu- 

 lar bands. The component cells are larger than those of the 

 clitellar glands, and very irregular ; they contain an irregular 

 nucleus, protoplasmic strands, and granular cytoplasm. The 

 ductules are exceedingly long and delicate, measuring in some 

 cases .125 mm. or more in length. Those from the dorsalmost 

 cells form an axis, about which the remaining cells are arranged 

 (Fig. II, ag). The groups of ductules (Fig. \i, d) from the 

 several glands converge toward the ventral side of the lower 

 lip, where they break up, and are distributed singly over the 

 surface and margin of the lip. 



Along the margins of both lips and within the mouth on the 

 lower lip, small groups of slender gland cells open. During 

 life these have a pale rose color and impart a decided tint to 

 this region. 



The functions of these two sets of head glands have not 

 been certainly determined ; but the habits of the animal sug- 

 gest that they secrete a sticky fluid used either to aid the lips 

 as adhesive organs, or to attach the cocoons, or both. 



Glands similar to those described by Dorner, and more fully 

 by Voigt, in Branchiobdella, are well developed in this species 

 in relation to the posterior sucker (Fig. 5, ag). The glandular 

 masses, which largely fill the tenth and eleventh and part of 

 the ninth somites, are pyriform, or aggregations of several 

 pyriform groups. Large, granular, lightly staining cell bodies 



