276 The Eneysiment of Bucephalus Haimeanus. 



nearly allied to the hop and nettles, the crystals in its leaf-blade 

 are composed chiefly of oxalate of lime, without any appreciable 

 trace of the carbonate, and the pith is devoid of sphseraphides. 



Some practical applications of these facts appear obvious. They 

 afford good examples of two kinds of crystalline concretions, differ- 

 ing as well in form as in chemical composition, existing in one and 

 the same plant ; that one use of the pith may be as a repository 

 and laboratory of sahne crystals, ready to be restored as manure 

 to the soil ; and that nettles and hop-bines should be thus utihzed. 

 Besides, the sph^raphides are so very beautiful, so easily examined 

 and preserved, as to afford an abundance of excellent materials, ever 

 at hand, for the employment of the microscope, and for preparations 

 to enrich the microscopic cabinet. 



Canterbury, Nov. 12, 1874. 



IV. — The Encystment of Bucephalus Haimeanus. 



By M. Ai.r. Giard. 



Von Baer pointed out long ago (1826) a peculiar parasite of the 

 Anodon, which he called Bucephalus polymorphus. This parasite 

 was later more fully described by Steenstrup and by Siebold, who 

 gave it its true place in classification. 



In 1854 M. Lacaze-Diithiers made known another species of the 

 same genus, the Bucephalus Haimeanus, which he had found in 

 the Mediterranean, and which lived parasitic in the genital glands 

 of the oyster (Ostrea eclulis), and also on the cockle (Cardium 

 rusticum), which it renders sterile. The sporocysts and the cer- 

 caria form of this Trematode have been very carefully figured in an 

 excellent paper in the ' Annales des Sciences Naturelles.' 



Claparede has since found this curious Trematode at Saint-Vaast- 

 la-Hogue, on the coast of Normandy.* It was in fishing in the 

 open sea with a very fine meshed net that he caught the Bu- 

 cephalus very frequently. The specimens drawn by Claparede differ 

 a little from those represented by M. Lacaze-Duthiers ; but this 

 difference, which bears principally on the form of the lamellar 

 appendages, did not appear important enough to the Genevese 

 savant to necessitate the creation of a new species, Claparede no 

 more than his predecessor has been able, in spite of his active 

 researches, to succeed in making known the final destiny of Cer- 

 caria Haimeana. 



* Claparede, Beobaclitungen uber Anatomie u. s. w. an der Kiizte von Nor- 

 maudi», 1863. 



