98 



On Ophryodendron abietinum. 

 By T. Strethill Wright, M. D. 



A very curious protozooii appeared about five years 

 ago in a limited locality, near Granton, on the southern 

 shores of the Frith of Forth, from whence it spreads upwards 

 towards Cramond, and now infests the Sertularite [S. pumila) 

 which abound for miles along the coast. I described it 

 in September, 1858, in a letter to Dr. Arlidge, one of the 

 editors of Pritchard^s ' Infusoria,' Avho has introduced it into 

 the last edition of that work, under the title of Corethria 

 sertularice (Wright) . I have also given a rough sketch of it 

 in the ' Edin. Phil. Journal' for July, 1859. Professor 

 Claparede, however, has informed me, that he and Lach- 

 mann had previously dejK^sited an account of it with the 

 Academy of Sciences of Paris. It will be found referred to 

 as Ophryodendron abietinum, in their recently published 

 studies,"^ and it is to be more fully described in the con- 

 cluding number of that excellent work. 



Both Claparede and Lachmann and myself have inde- 

 pendently placed this creature among the Acinetinians, but 

 not without considerable doubt, as it differs so widelv in 

 shape and habits from all others of that family. Dr. Arlidge 

 writes to me, that " tliere is something so bizarre about the 

 organism that I cannot interpret it." 



The body of the animal consists of an oblong mass attached 

 to the polypidom of the Sertularia (Plate VI, fig. 1). From 

 one end bf the mass arises a closely Avrinkled appendage or 

 proboscis, surmounted by a tuft of short tentacles. Such is the 

 general appearance of the animal ; but a second appendage 

 is frequently present, which appears to be a gemma, as it 

 is sometimes foimd separated from the animal, and at- 

 tached to the Sertularia. 



When I described this protozoon in 1859, I had not seen 

 any motion in the proboscis ; but, during the last summer, 

 when I kept a number of OjjJiryodendra in large vessels of sea- 

 water, I was surprised to find the organ in constant motion, 

 sometimes almost withdrawn into the body, and again, at 

 other times, extended to an astonishing length, until it 

 became a clear glassy wand, thirty times as long as the body, 

 and clothed at its upper end by about forty scattered tentacles, 

 which twined about in most violent motion. The animal 



* 'Etudes sur les lufusoii-es et !es Rliizopocies,' par Edouard Claparede 

 el Johannes Laclima'nn. 



