i894. SOME NEW BOOKS. 233 



plate representing a bizarre-looking Selachian, captured at Buarcos. 

 Mr. G. A. Boulenger, of the British Museum, who was consulted, 

 refers it to Squalus vostmtus, Marc, which Dr. Giinther identifies with 

 Selache maxima. Dr. Lopes Vieira, who gives an account of the speci- 

 men, is as yet by no means satisfied with the identification. From 

 the figure and details given we are inclined to agree that if it is Selache 

 maxima it is a very abnormal specimen. 



In the last number of the Journal of Anatomy and Physiology, Mr. F. G. 

 Parsons describes the tendo achillis of mammals, as being formed by 

 a rope-like twisting of the fibres derived from the two heads of the 

 gastrocnemius, the soleus, and the plantaris. The twisting which can 

 be made out in man he regards as being partly due to the rotation of 

 the limb in the embryo, but more largely to the position of the foot in 

 the uterus of the mother. 



Dr. a. Grandidier has issued two more volumes of plates illustra- 

 ting the natural history of Madagascar. These are the fourth and 

 fifth volumes of " Histoire Naturelle des Plantes," By H. Baillon. 

 Once more we regret to observe that the plates are unaccompanied 

 by any text or explanation. 



In the American Journal of Science for August, 1894, Mr. O. L. 

 Simmons, of Tufts College, Mass., writes on the " Development of 

 the Lungs of Spiders." He comes to the conclusion that " the lung- 

 book of the spider, and presumably of all arachnids which possess 

 one, arises at first as an external structure upon the posterior surface 

 of the abdominal appendages. These appendages sink in without any 

 inversion or complications, in exactly the manner theoretically 

 deemed probable by Kingsley, so that there can no longer be any 

 doubt as to the exact homology existing between the lungs of the 

 spider and the first pair of gills in Limulus." 



The beautiful little fresh-water alga Volvox is well-known to lovers 

 of ditch and pond life. We see from the July number of The Botanical 

 Gazette that Mr. W. F. Shaw has found in a ditch at Palo Alto, 

 California, an allied plant, which he considers to be and describes 

 as a new genus, Pleodorina. The name indicates its affinity with 

 Eudorina. It resembles Volvox more than does the latter genus in 

 the number of cells composing the individual and the specialisation 

 of certain cells for the purpose of reproduction. No sexual genera- 

 tion has, however, yet been observed. 



