mVERTEBEATA, CRYPTOGAMIA, MICROSCOPY, ETC. 93 



The mode of life of these creatures wovild not be so remarkable 

 were it not that both inhabitants of the cyst are in all respects similar ; 

 the history of their development is as yet unknoAvn, The integument 

 is extraordinarily thin, and consists of a fine cuticle and of finely 

 granular protoplasm. The parenchyma proper forms a Avide-meshed 

 network, and there is on it a system of larger and smaller spaces in 

 which the organs of the body are set. The mouth is jilaced at the 

 anterior end of the body and leads into a pharynx, which may be 

 roimded or may be elongated, and is best develoiDcd in D. pelamydis. 

 When the enteric tract is developed the oesophagus is, as ordinarily, 

 bifurcate, and ends blindly at the hinder end of the body. With 

 regard to the absence in some species of any enteric tract, it is of 

 interest to note that where it is present, there is no indication of any 

 lining epithelium; the generative organs occupy the greater part of 

 the body, but no ovary could be observed ; in all cases observed the 

 eggs were already well-developed ; the oviduct oj^ens at the anterior 

 end, and the seminal duct opens in the same region. The paper is 

 illustrated by a plate of five figures. 



Contributions to American Helmiiithology.* — Professor Eamsay 

 Wright describes the following new species : Distomum asperum, from 

 the bile-duct of Bofaurus minor ; D. reticulatum, from the surface of 

 the lung of the belted kingfisher ; Polystomum ohlongum, from the 

 urinary bladder of the musk-turtle ; and Filaria triaenucha, from the 

 proveutriculus of the bittern. Sphyranura Osleri is the name given to 

 the representatives of a new genus, which were taken from the gills 

 and buccal cavity of the common lake-lizard {Menohranclms lateralis) ; 

 this appears to be the only form of monogenetic Trematode, with 

 the exception of Polystomum integerriynum, which has yet been 

 found in any amphibian ; the author takes occasion to point out 

 that the resemblance of the Polystomimi-larva to Gyrodactylus is very 

 striking, and he draws attention to the fact that " if the piscine 

 ancestors of Amphibia had Gyrodactylus-like gill-parasites these 

 would probably be transmitted to their descendants." Other already 

 known forms are also referred to in the paper. 



Ecliinodermata. 

 Studies on the Ecliinodermata. f— Dr. Hubert Ludwig publishes 

 a preliminary notice of the contents of the first part of the second 

 volume of his ' Morpliological Studies on the Echinodermata.' Ho 

 has arrived at the following results ; — 



(1) The stalked larva of Antedon has, primitively, only one 

 stone-canal and only one pore ; these always occupy the same inter- 

 radius, and that the one next to that in which the rectum and anal 

 orifice are placed ; this relation of parts is also seen in the Astcrida. 

 As the primary pore of the Crinoida lies in an oral plate, it follows 

 that the oral plates of the Comatulida; liave the same relation to the 

 water-vascular system as the genital plates of the Echinoidca and 

 Asterida. 



(2) In all Echinodermata the coils of the enteric tract take tho 



• 'CanndiftD Jdurn.,' i. (1870) p. 54. f ''/'WA. Anzriger,' ii.(187a) p. 540. 



