400 "'^- MOHTENSKN. 



see any reason to regard these cells as glandular, as is done by 

 Salensky; probably they represent traces of an original arrangement 

 of the cells in regular longitudinal rows, as described by Nitsche 

 in Loxosoma Kefersteinii Clap. (Über die Knospung der Bryozoen. 

 Zeitschr. f. wiss. Zool. XXV. 1876. p. 142. Taf. XXV. Fig. 7) and by 

 Harmer in L. Tethyce Sal. (Structure and development of Loxosoma. 

 Quart. Journ. Micr. Sc. N. Ser. XXV. 1885. PI. XIX. Fig. 9). The 

 cuticula of the stalk is irregularly ringed, probably the result of the 

 contraction on preservation. 



The musculature of the stalk is not very strongly developed, 

 consisting only of longitudinal muscles, arranged in a single layer 

 all round inside the epidermis. Oblique muscles, so conspicuous in 

 the species L. annelidicola (v. Ben. & Hesse) and L. Davenporti Nic- 

 kerson, are not developed. This slight development of the muscu- 

 lature is in fair accordance with the fact that the animal is fixed 

 for life; the same condition is found in L. crassicauda Sal. which is 

 likewise fixed for life by a secretion from the foot-gland present in 

 the bud, but atrophying after the fixation of the animal, while both 

 L. annelidicola and L. Davenporti remain free and are able to change 

 their position. 



The structure of the muscles is very peculiar. On sections of 

 the stalk the muscle cells are seen to contain numerous fine fibres, 

 arranged in a circle along the periphery (Fig. 7). So far as I am 

 aw^are, such a structure of the muscles has not hitherto been ob- 

 served in any species of Loxosoma. On the other hand a quite simi- 

 lar structure of the muscles has been described by Davenport in 

 Urnatella gracilis Leidy (Bull. Mus. Comp. Zool. XXIV. 1893. p. 5. 

 PI. II. Figs. 9 — 11, 16 — 17), and also in Ascopodaria macropus Ehlers 

 a similar arrangement of the muscle fibres appears to exist, the 

 musculature being, otherwise, much more developed in this form. 

 (Cf. E. Ehlers. Zur Kenntnis der Pedicellineen. Abb. d. Ges. d. Wiss. 

 Göttingen. XXXVI. 1890. p. 25. Taf. 1. Fig. 12—14). It may then not 

 be unreasonable to suggest, that the same structure of the muscles 

 will prove to occur also in other forms — if not in all — of the 

 Entoprocla. 



On each side of the calyx, about at the level of the mouth 

 opening, are found 1 — 3 large glandular cells (Fig. 8); the plasma is 

 finely granular, and a rather large nucleus lies at the bottom of the 

 cell. Together with these glandular cells is found a small papilla 

 of a peculiar structure, one on each side of the body (Figs. 2 — 4, 6). 

 In the interior of the papilla is seen a large nucleus and outside 

 this the plasma appears to be compact and dark, while in the rest 

 of the organ it is quite hyaline. — These papillæ are doubtless the 



