Febbuakt 18, 1910] 



SCIENCE 



265 



and Liitken believed. Jungersen has shown 

 conclusively that these early findings were 

 based upon immature specimens. I know of 

 no trustworthy evidence that the whale-shark 

 " realizes the length of some seventy feet " : it 

 probably does not exceed fifty feet or there- 

 abouts. There is, as far as I am aware, no 

 " embryological evidence that the hyomandib- 

 ular element in Holocephala has fused with 

 the skull." The early forms like Pterichthys 

 are not, I am convinced, separated from 

 Coccosteids on the grounds which are in- 

 stanced, pp. 260-261, though this is a mat- 

 ter upon which opinions of specialists may 

 differ. " Palwospondylus can not be a larva 

 on account of the centra present," but it 

 is none the less a fact that larval forms, fish 

 or amphibian, are not uncommon in which 

 well-grown centra are present. Goodrich 

 again assumes a " pineal eye " in petromy- 

 zonts, though it is only fair to admit that this 

 organ may not sensu stricio be an eye at all, 

 perhaps it is a temperature-appreciating or- 

 gan, for one can hardly call an organ an 

 " eye " in which a dense screen of pigment 

 separates the image — if there be an image — 

 from the sensory cells. On page 125 we read 

 that " the main lateral line of the trunk runs 

 forward on to the head " : a better reading per- 

 haps would have been that the main lateral 

 line runs backward from the head, in view of 

 the development of this organ. It is stated 

 that the " yolk-sac of the Selachian protrudes 

 from the ventral surface of the embryo often 

 after birth," a condition which, I believe, does 

 not normally occur. At least I have observed 

 that in six species (in three different families) 

 the young show at birth nothing more con- 

 spicuous than a scar to mark the disappear- 

 ance of the sac. 



In several details of terminology I am not 

 sure that Goodrich has lessened our troubles. 

 In certain cases he has created a series of 

 popular names for groups whose technical 

 names are already widely accepted, in some 

 cases classic. Thus why should we adopt 

 " Petromyzontia " and " Myxinoidea " for 

 the well-known Miillerian names Hyper- 

 oartia and Hyperotreta? Nor is he con- 



sistent in his effort toward popularization, 

 when he devises complicated technical names 

 where simpler ones seem adequate. Thus 

 in the matter of the fin supports of fishes 

 he usually discards the well-known " radials," 

 " basals " and " actinotriches " (or plain 

 " dermal rays," to distinguish them from 

 obvious skeletal rays), for such new names 

 as " dermoptrichia," " somactidia," " lepido- 

 trichia." Indeed it is not quite clear that 

 these terms are as specific as the author im- 

 plies. We query whether the criterion of 

 their homology is to be based upon the details 

 of structure instanced, for we recall that the 

 homology of the bones of teleosts can not be 

 determined on such finely-spun histological 

 distinctions. Indeed, Goodrich himself reverts 

 to the homely " radials " and " basals " when 

 he is not on his guard (p. 302). He occasion- 

 ally uses names for various structures which 

 are far more questionable in point of homology 

 than the fin supports noted above. Thus he 

 refers throughout to " clavicle," " coracoid " 

 and " scapula " in fishes, although specialists 

 by no means agree as to their homologies in 

 the cheiropterygian girdle. 



His treatment of the teleosts will not escape 

 criticism. Certain it is that he has cut sev- 

 eral of the Gordian knots in which the despair- 

 ing phylogenist has been entangled. Thus, 

 undaunted by convergence, he adopts numer- 

 ous (about twenty) group-names ending in 

 " formes " — Notacanthiformes, Perciformes, 

 Beryciformes — and from this point of view 

 gives us a very useful summary of the groups, 

 perhaps the best of its kind. This mode of 

 treatment has clearly the merit of conve- 

 nience — too great convenience, perhaps, for 

 we doubt whether it expresses adequately our 

 present knowledge of teleostean interrelation- 

 ships. Bashford Dean 



A Hand-list of the Genera and Species of 

 Birds. (JSTomenclator Avium tum Possilium 

 turn Viventium.) By E. Bowdler Sharpe, 

 LL.D., Assistant Keeper, Department of 

 Zoology, British Museum. Volume V. Lon- 

 don, printed by order of the trustees. Sold 

 by Longmans & Co., 39 Paternoster Row, 



