



1891.] Zoology. 835 
ignore the Ascidiz: Compositz of our text-books, although the division 
may be retained for convenience. 
Walter Garstang’ gives the first part of a review of the Tunicata of 
Plymouth, England. Species of the families Clavellinidz, Peropho- “ 
ride, and Diazonidz are enumerated and described at length. 
Pycnoclavella is a new genus. 
A. Herdman promises a monograph of the British Tunicates. 
The Affinities of Polypterus.—H. B. Pollard has studied some 
points in the structure of Polypterus which, he thinks, throw light 
upon the relationships of this form. The ear, except in lacking the 
ductus endolymphaticus, is distinctly Urodele in its character, as is 
shown by the immense sacculus, which reaches the level with the semi- 
circular canals, and by proximal division of the auditory nerve. The 
so-called opisthotic corresponds to the Urodele petrosum ; the opthal- 
micus profundus and superficialis pass through a foramen into the 
nasal capsule ; the supracranial fontanelle is partially roofed over by 
cartilage ; the ‘‘ paired vomer’’ is really dermopalatine, and corre- 
sponds to the so-called vomer of the Batrachia. The jaw muscles corre- 
spond to the Batrachian rather than the Teleostome type, while the 
nervous system corresponds almost to detail with that of larval Sala- 
mandra. The conclusion to be drawn from these facts is that the 
ancestry of the Urodeles must be sought in Crossopterpgians. Turn- 
ing now to the affinities of the other piscine forms, Pollard promises to 
show homologies of Polypterus with the Stegocephali, while the posi- 
tion of the Dipnoi and Holocephali must be different from that usually 
accorded them. Chimera, etc., are Dipnoan forms which have lost 
their dermal bones, and are retrograded in some respects toward the 
Selachian type. If the Dipnoan formsare to be regarded as ancestors of 
the Batrachia, we should expect to find in the larval Urodeles the 
same relations of quadrate and palatines to the cranium, but such 
is not the case. In the young Cryptobranchus the quadrate has nearly 
the same relationships as in Polypterus. The suprapharyngobranchial I. 
articulates with the auditory capsule, and from it the author traces the 
origin of the Urodele stapes. This paper isasample of the errors into 
which it is easy to fall in ignorance of the facts of paleontology. 
The Pineal Organ of Ichthyophis and Protopterus.— 
_ Burckhardt thinks? that all previous authors have mistaken an arterial 

T Jour. Marine Biol. Assn. United Kingdom, 1891, Vol. II., p. 47. 
8 Anat, Anzeizer, VI., 338, 1891.. 
9 Anat. Anzeiger, VI., 348, 1891. 



