BihliograpMcal Notice. 193 



EXPLANATION OF PLATE IX. 



Fig. 1. Liltkema arctica,irova. above. Natural size. 

 Fig. 2. Li'dhenia arctica, from below. Natural size. 

 Fig. .5. Mouth-shield, side mouth-shields, jaw-angles, and mouth-papilltb 



and tooth-papillse. Magnified 2 diameters. 

 Fig. 4. Tooth-papillaj, from below and obliquely. Magnified 2 diam. 

 Fig. 4 a. Representatives of the teeth, from above. Magnified 2 diam. 

 Fig. 5. Lower arm-plates and side arm-plates. Magnified 2 diam. 

 Fig. 6. Side arm-plates and spines. Magnified 2 diam. 

 Fig. 7. Upper arm-plates. Magnified 2 diam. 



BIBLIOGRAPHICAL NOTICE. 



A Manual of Zoology for iJie Use of Students, with a General Intro- 

 duction on the Principles of Zoology. By Hexry Alletne 

 Nicholson, M.D., D.Sc, M.A., Ph.D., E.R.S.E., E.G.S. Fifth 

 Edition, revised and enlarged. 8vo. Blackwoods ; Edinburgh 

 and London, 1878. 



We welcome the appearance of this new edition of Prof. Nicholson's 

 ' Manual of Zoology,' of some previous issues of which we have 

 had occasion to speak in terms of praise. As a general systematic 

 ti'eatise on the structure and classification of animals it is the best 

 that we possess ; aud the author's industry has enabled him in the 

 present edition, which is much enlarged, to improve his work very 

 greatly. Still the Avork is rather a manual of animal morphology 

 for the use of students than a treatise on zoology in the broad sen.se 

 of the term ; but we must be thankful for what we get, and it 

 must be confessed that it would be impossible, even within the 

 limits of the present enlarged volume, to combine an equally satis- 

 factory account of the organization, development, and structure of 

 animals with a good sketch of their relations to each other and to 

 the outer world. In this latter particular we are nevertheless glad 

 to see that Prof. Nicholson has now gone further than in previous 

 editions. The increase in the number of pages is considerable ; but 

 besides this the author has further gained space by printing certain 

 portions of his work in small type. 



In its general arrangement this edition differs so little from its 

 predecessors as not to require any detailed notice. On nearly every 

 page, however, we find traces of alterations made in consequence of 

 recent researches in different branches of zoology : the chapters on 

 Sponges and Hydroids and on Entozoa seem to have received great 

 additions ; and the results of the recent investigations of the Ame- 

 rican palaeontologists upon the rich accumulations of vertebrate 

 remains found in their Secondary and Tertiary rocks have led to 

 considerable additions being made to the chapters on Yertebrata, 

 We notice that that mo.st unnatural group, the Annuloida, still 

 figures as a primary division of the animal kingdom ; let us hope 

 that it will disappear from the next edition, as its founder may be 

 considered to have already given it up. 



Ann. & Maej. N. IL'sf. 8er. 5. Vol. ii. I'd 



