ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 59 



seems to be skipped over. The vesiele appears to be protective, like an 

 amnion, and encloses the scolex in a receptaculum capitis ; it has great 

 vitality, and was seen to be mobile in T. ruficollis. Sometimes there is 

 a false jointing, like precocious assumption of the adult form, though 

 the results are not utilised in the subsequent development. If the first 

 host be devoured by one unsuited to the further development of the 

 parasite, the larva is usually digested ; but in some cases it seems to con- 

 tinue to live without developing, as in T. mulli-barbati in Mullus barbatus. 

 If the second host be suitable, the scolex developes into a strobila, usually 

 fixed to the walls of the intestine by its proboscis-organs, but sometimes 

 remaining in the pyloric region. The larval form does considerable 

 damage, e.g. T. gigas in the liver of Mola ; but the adult does little if 

 any harm. In fact, as Van Beneden remarked, the finest fish often have 

 most parasites. 



Vaullegeard groups the species around the following types : — 

 T. lingualis, T. megacephalus, T. tetrabothrius, T. tenuis, T. erinaceus, 

 T. ruficollis, and T. minutus, but there remain many doubtful species. 

 He discusses the affinities of Cestodes, and places the Tetrarhynchi 

 nearest the Phyllobothrise. It should be noted that this useful memoir, 

 which brings together what has been established in regard to these 

 remarkable Cestodes, also adds much in regard to the minute structure 

 and the life-history of particular species. 



Two New Bird Tapeworms.* — 0. Fuhrmann has added two strange 

 forms to the number of remarkable tapeworms found in birds. The 

 first, Gyroccelia perversus g. et sp. n., is characterised by the disposition 

 of the musculature in the parenchyma — two layers of longitudinal 

 muscles alternating with three layers of transverse muscles — by the 

 absence of a vagina, and by the annular uterus with a ventral and a 

 dorsal opening. The second, Acoleus armatus g. et sp. n., is also re- 

 markable in its musculature, and in having an enormous seminal sac 

 and no vagina. Perhaps, along with Taenia polymorpha Rud., they 

 should be referred to a new family, Acoleinae. All three were got in 

 hosts belonging to the order of " Waders " (Limosa, Himantopus, &c). 



Cestodes from Birds.f — Dr. Ludwig Cohn publishes a note on certain 

 disputed points in regard to the classification of Avian Cestodes. The 

 points discussed are especially the taxonomic value of the number of 

 hooks as contrasted with the value of their variations in form, and the 

 question as to whether the rule of priority applies to sub-generic names. 

 Cohn strongly maintains the affirmative position in regard to the latter 

 question, but is not prepared to accept the British Association Code in 

 its ruling as to sub-genera. He accepts, however, the ruling of the 

 International Commission that " the name of the typical sub-genus is the 

 name of the genus." 



Clinostomum.J — Prof. M. Braun discusses the value of this genus, 

 and accepts it as based on the structure of the anterior end of the body, 

 of the excretory system, and of the sexual organs. All the species, when 

 sexually mature, live in the mouth-cavity or throat of the Ardeidae and 

 Ciconiidse, while the encysted young forms live in fresh-water bony fish. 



* Rev. Suisse Zool., vii. (1809) pp. 343-51 (1 pi.). 



t Zool. Anzeig., xxii. (1899) pp. 405-8. I Tom. cit., pp. 484-8, 489-93. 



