33 [Shurtleff. 



Dr. Shurtleff, in connection with the change of phimage in 

 the pea-hen communicated at the last meeting, mentioned 

 the case of a black hen of the common fowl, which, after 

 having been twice prevented from sitting, seemed to lose the 

 power of laying, and assumed the plumage of the cock. The 

 neck feathers first became golden, the spurs were lenQ;thened 

 and the tail feathers elongated. She was finally killed by 

 mistake for a cock. 



The President communicated the results of some recent 

 investigations by himself and others in relation to the anat- 

 omical distribution of the nervous filaments in vertebrate 

 animals, and instances of their passage across the median Hue 

 of the body. 



Mr. Bouve announced the recent decease of Prof Hitch- 

 cock, an honorary member of the Society, and moved the 

 appointment of a Committee to prepare resolutions suited to 

 the event. 



The President appointed Messrs. Bouve and C. T. Jackson. 



Dr. A. A. Gould presented a communication 



Ox THE OCCURRENCE OF AN INTERNAL CONVOLUTED PLATE 

 WITHIN THE BODY OF CERTAIN SPECIES OF CrINOIDEA, BY 



James Hall. 



During the investigations upon the Crinoidea of the Carboniferous 

 Limestones of Iowa, there were discovered in the broken bodies of 

 several species, a vertical convoluted plate, tilling a large part of the 

 cavity of the body. At that time I showed several of these specimens 

 to Prof. Agassi z, wVio informed me that he had observed a similar con- 

 voluted plate in the body of Comatula. 



This convoluted intestinal plate was first observed in the body of 

 Acttnocrinus pentar/onus, -dnd afterwards in Actinocrlnus lonr/irostris, 

 Act. erodus, Act. VerneuUl and in a species of the type of Act. um- 

 brosus. In several of the specimens, and this is apparently true of all 

 the Actinocriniis, the opening into this convoluted sac is wider at the 

 apex, and becomes gradually attenuated below and pointed towards 

 the centre of the basal plates where it is attached. The lower por- 

 tion is twisted not unlike the lower portion of some univalve shells, 

 and this organ, in one specimen, presents a very close resemblance to 

 a small Bulla or similar shell. In Actinocrlnus lonr/lrostrls this organ 

 is proportionately very large, the sides straighter and less curved, and 

 very wide at the top. 



PROCEEDINGS B, S. I^". H.— VOL. X. 3 KOVEMBER, 1865. 



