334 ME. J. S. BUDGET! 1 ON SOME POINTS IN 



X. The Cranium. 



In this paper I have no intention of dealing with the anatomy of the head and 

 cranium of Polypterus, except that I wish to mention that the peculiar differences 

 in the condition of the sphenoid bone which Bridge has described in two specimens 

 which he examined, and called specimen A and specimen B, have been found to be 

 specific in the two species from the Gambia. The sphenoid bone of Bridge's specimen 

 A, resembling that figured by Traquair, in which the lateral wings of the sphenoid did 

 not curve inwards and fuse anteriorly in the frontal region, resembles exactly that of 

 Polypterus senegalus, Cuv. The sphenoid (or " sphenethmoid ") bone of Bridge's 

 specimen B, which he suspected of being Polypterus lapradei, Steind., resembles 

 exactly that species 1 . 



XL Conclusion. 



If in this paper I have occasionally reiterated facts which have long been known, 

 I trust such has not been done without adding at least some details of interest. In 

 any case I hope I have always acknowledged the authority. 



I feel that no apology is needed for having entered into minute details in some cases, 

 for an accurate knowledge of the anatomy of a creature of such surpassing interest as 

 the Polypterus seems to me in every way desirable. 



In obtaining my material for this investigation I have been aided by a grant of £50 

 from the Balfour Fund of the University of Cambridge. The work has been done 

 in Mr. Adam Sedgwick's laboratory. To Mr. Sedgwick, Mr. Graham Kerr, and 

 Prof. Howes my thanks are due for much help and advice in my work. 



XII. Bibliography. 



Ayers: "Morphology of the Carotids," in Bull. Mus. Comp. Zool. Harvard, vol. xvii., 1889. 



Balfour : ' Comp. Embryology/ vol. ii. p. 606. 



Balfour and Parker : " The Structure and Development of Lepidosteus.'" Phil. Trans. Roy. Soc. 



Lond. part ii., 1882. 

 Bridge, T. W. : " Some points in the Cranial Anatomy of Polypterus," in Birm. Phil. Soc. vol. vi. 



part i., 1886. 

 Carman : " Chlamydoselachus anguineus" in Bull. Mus. Comp. Zool. Harvard, vol. xii., 1885. 

 Howes : " On some Hermaphrodite Genitalia of the Codfish." Journ. Linn. Soc, Zool. vol. xxiii. 

 Huxley : " Classif. of Devonian Fishes," in Mem. Geol. Survey, dec. 10, 1861. 



" On the Oviducts of Osmerus." Proc. Zool. Soc. Lond. 1883, p. 132. 

 Hyrtl: " Ueher d. Pori abdominales, d. Kiemen-Arterien, u. d. Glandula thyroidea d. Ganoiden." 



Sitz. d. Wiener Akad. Bd. viii., 1852. 



1 Since this paper was read, I have examined a young specimen of P. lapradei 12 cm. in length, and find 

 that at this age the sphenoid has not yet developed its specific character, hut resembles that of the adult 

 P. senegalus. 



