1878.] 



On the Temperature of the Head. 



457 



2. The asteroid character of the ambulacral system : the divisional 

 plates not only being homologous with, but resembling in the manner of 

 their disposition the ambulacral plates of Asteroidea ; at the same time 

 furnishing a highly suggestive representation of their phylogenetic 

 development. 



3. The rudimentary structure of the mouth-armature, more aste- 

 roid than ophiuroid in general facies. Absence of teeth, jaw-plates, 

 and jaws. 



4. Extension of the peritoneal cavity to the extremity of the func- 

 tional portion of the rays, that is to say, to the margin of the pen- 

 tagonal body. 



5. The extremely rudimentary condition ai)d aborted character of 

 that portion of the brachial series which is prolonged beyond the body- 

 disk. 



6. The continuity of the tentacular pore-system limited to the disk 

 only. 



The above characters are clearly sufficient to stamp the peculiarity 

 of this extraordinary echinoderm, and, whilst excluding it from any 

 known group of genera by their remarkable nature and by the aber- 

 rant departure they present from all previous types, are such as would 

 seem to necessitate the relegation of the form to a family apart by 

 itself. 



To speak definitely as to the exact position of intermediacy which 

 the organism holds between the Asteroidea and Ophiuroidea would 

 obviously be premature, without a more detailed examination of the 

 internal anatomy than the present specimen in its dry condition will 

 permit, as well as some knowledge of the life-history of the form. It 

 may however be safely affirmed without overstepping the bounds of 

 due caution, that Astrophiura bridges further over, from the ophiuroid 

 side, the differences which have separated the two orders, than any 

 previously described starfish or brittle-star. 



VI. "Experimental Researches on the Temperature of the 

 Head." Part II, III, IV. By J. S. Lombard, M.D., formerly 

 Assistant Professor of Physiology in Harvard University, 

 U.S. Communicated by H. Charlton Bastian, M.D., 

 F.R.S., Professor of Pathological Anatomy in University 

 College, London. Received June 18, 1878. 



(Abstract.) 



Part II. — 'Examination of the Middle Region of the Head. 

 This region is divided on each side into 7 tiers by G equidistant 

 lines drawn parallel to the longitudinal median line. The tiers are 

 vol. xxvii. 2 H 



