48 JOURNAL OF MARINE ZOOLOGY AND MICROSCOPY. 



Tribe I. — Pedunculata ; stalked, six pairs thoracic limbs. 



Families. — Lepadidce (stalks without calcareous plates or 

 hairs) ; and Pollicepedidce (stalks with hairs or 

 plates). 

 Tribe II. — Operculata ; sessile, limbs same as in Pedunculata. 

 Families. — Balanidce and Chthamalidce (closely related, 

 both with a symmetric calcareous ring, each 

 branchia a single fold) ; Coronulidce (symmetric 

 ring of plates, each branchia doubly folded) ; Ver- 

 rucidce (calcareous ring asymmetric). 

 Tribe III. — Abdominalia ; thorax reduced, bearing three pairs 

 of cirriform limbs. 

 Family I. — Alcippidce, four pairs thoracic limbs, three 



pairs being cirriform. 

 Family II. — Cryptophialidce, three pairs only of thoracic 

 appendages — all cirriform. 

 Tribe IV. — Apoda ; no thoracic limbs, grub-like. 

 Family. — Proteolepadidce. 

 Sub-Order II. — Rhizocephala ; parasitic — body sac-like — without 

 mouth or alimentary canal ; possessing root-like 

 processes that ramify in the viscera of the host. 

 One family only. — -Kentrogonidce. The chief genera are 

 Peltogaster, parasitic on Hermit Crabs, and Sac- 

 culina, parasitic on Cancer, Garcinus, &c. 



BOOK NOTICE. 



"Elementary Physiology" by Prof. J. B. Ainsworth Davis, 223 pp., 3 coloured 

 plates and 104 figures in test. (London ; Blackie & Son, Ld., 1895). Price 2/-. 



Practical zeal and discrimination are impressed so characteristically upon all 

 work undertaken by Prof. Ainsworth Davis, that one is inclined to accord this little 

 work a hearty welcome on the strength of the author's credit alone. Detailed 

 examination confirms this view, and as an introductory test-book, we believe it to 

 be quite the best of its class. One cannot be too thankful to the author for the 

 stress with which he emphasizes the fact that Human Physiology is but a small 

 portion of Animal Physiology — too many students have, in the past, unconsciously 

 grown into the belief that the two are interchangeable terms. Prof. Davis takes 

 a very practical way of clinching his warning, by introducing an ably written 

 chapter upon the digestion of the ox, and the secretion of milk. This is as it ought 

 to be. In the chapter on practical work, the innovation is carried further still, for 

 the frog, rabbit, rat, sheep, and bullock are all pressed into service, and so induce 

 the requisite comprehension that all the vertebrates, including man, are upon 

 essentially the same plan. 



The work is well and judiciously illustrated, and while invaluable to those 

 entering upon the study of this particular science, it ought also to be in the hands 

 of every intelligent person interested in the way his own body is built up. It will 

 also be invaluable to agricultural students, and specially to those engaged in 

 dairying. 



A good index, and two sets of examination questions are appended. 



