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POPULAR SCIENCE REVIEW. 
Classification of Rodents. — Herr Fitzinger has presented the second part of 
his memoir on this subject to the Vienna Academy. The natural families 
he establishes are (1) Mures, (2) Hypudaei, (3) Castores, (4) Dispodes, (5) 
Eryomes, (6) Psammoryctse, (7) Hystrices, (8) Cavice, (9) Lepores. — Vide 
V Institute December 26, 1867. 
Circulatory Apparatus of Starfish. — M. Jourdain has been publishing the 
results of his researches on this part of the anatomy of Astei'acanthion ruhens. 
He corroborates Milne Edwards’ statement that the general cavity of the 
body is closed. This cavity contains a liquid holding in suspension numerous 
yellow globules, of about the ^th of a millimetre. These globules are set in 
motion by the vibratile cilia which clothe the surface of the general cavity 
and direct the currents, exactly as was pointed out years ago by Dr. Sharpey, 
of University College. In the integument may be seen a number of ca3ca, 
distributed in groups about 2 millimetres long, and which are diverticula of 
the cavity. These, from his experiments on them, M. Jourdain styles respi- 
ratory ccBca. He states that he has failed to find the complex vascular system 
described by Tiedemann andVolkmann, and he expresses considerable doubt 
as to its existence. The so-called heart of the star-fish ho has described 
to be nothing more than a glandular mass, whose supposed blood-vessels 
are only muscles and tendons. He denies also the existence of more than 
one huccal vascular ring., which he says is connected with a series of tubes 
quite distinct from the general cavity, — Vide Proces Verhaux of the Societe 
Philomathique of Paris for 1867, Institut, December 26. 
Professor Huxley's Lectures on Invertebrates, which have been delivered 
before the College of Surgeons, should be read by all zoologists. Clear 
abstracts of them have appeared in the Medical Times and Gazette for 
February and March. 
