A PROF. ALLMAN ON THE 



especially called attention to the relations of the intestine, which 

 in these genera opens, like the mouth, within the tentacular crown. 

 This character thus becomes the index of a very distinct type of 

 structure, in accordance with which Nitsche divides the Polyzoa 

 into two great sections : — the Endoprocta, in which, as in Pedi- 

 cellina, the intestine opens within the tentacular crown ; and the 

 Ectoprocta, in which, as in the great majority of the Polyzoa, it 

 opens outside of the crown. 



Besides the long-known Pedicellina and the more recently dis- 

 covered Loxosoma of Keferstein and Claparede, the group of the 

 Endoprocta now embraces the beautiful freshwater genus Ubna- 

 tella, described by Leidy*; while to the same group must be 

 referred the remarkable marine genus Ascopodaria, Busk MS., 

 determined and carefully investigated by Busk in specimens from 

 the ' Challenger ' Expedition, but not yet made the subject of a 

 published notice. 



Loxosoma has recently been studied by Oscar Schmidt f , who 

 believes that he finds evidence that the apparent buds in this 

 genus are really eggs detached from the ovary and developed on 

 the body of the parent — a view which cannot be reconciled with 

 other observations, especially those of Nitsche and of Salensky, 

 who found such buds borne by other buds, in which, in consequence 

 of their immature state, no ova could have as yet existed. 



Salensky J has described two new species of Loxosoma, and has 

 made some important observations regarding the structure of this 

 genus. Like all the other endoproctal forms, Loxosoma consists 

 of a cup-shaped body supported on a peduncle. The peduncle 

 consists of a parenchyma and a muscular layer surrounded by a 

 cellular layer (endocyst), which is overlain by a homogeneous 

 membranous layer (ectocyst). Its form differs much in the two 

 species described by him. In one (L. Tetliym) the peduncle is 

 provided with a terminal gland-like organ ; in the other (L. cras- 

 sicauda) no such organ exists. L. crassicauda, however, fixes 

 itself by means of a hardened homogeneous secretion, probably 

 produced while the animal is young, and before the disappearance 

 of the peduncular gland. The fixation of the animal by means of 

 such a secretion seems to be characteristic of the species ; for the 



* " On Urnatella gracilis," in Proc. Acad. Sc. Philad. vol. ni. p. 191 (1854). 

 t Arch. f. mikr. Anat. Bd. xii. p! 1 (1875). 



\ Salensky, " Etudes sur les Bryozoaires Entoproctes," Ann. Sc. Nat. 6 rae 

 ser. tome v. 1877. 



