88 University of California Publications in Geology [Vol. 13 



It would be premature to attempt to set forth the relationships of 

 the Monachinae with other phocids until we can trace their ancestral 

 history by means of fossil forms. However, in studying the osteo- 

 logical characteristics of the various known forms, several points 

 clearly present themselves. The humerus is more like that character- 

 istic of the Cystophorinae, though in cranial and other skeletal features 

 it is even more widely separated from the latter than from the 

 Phocinae. One observes that the number of incisors, the peculiar form 

 and reduced size of the auditory bullae, and the similar prolongation 

 backward of the malar process of the maxilla, as pointed out by 

 Allen 175 are points of similarity with the Antarctic Lobodoninae, which 

 differ as much from each other as they do from Monachus. 



The presence of Monachus schauinslandi 176 in the Pacific Ocean, 

 particularly in the vicinity of Laysan Island, shows that the Mon- 

 achinae must have had a very extensive distribution in the tropical 

 seas as early as or even before the Lower Miocene. Otherwise, it wovdd 

 be difficult to account for their presence today in the Pacific Ocean. 

 Another form, Monachus tropicalis, 177 occurs at Yucatan, Florida, 

 Jamaica, and Cuba, its range being restricted chiefly to the Caribbean 

 Sea and the Gulf of Mexico. The European form, Monachus albi- 

 venter, 176 ranges from the Black, Adriatic and Mediterranean seas to 

 the Canary Islands, and possibly farther south along the east coast 

 of Africa. 



In some respects the Monachinae appear to be related to the 

 Otariidae. This relationship is indicated by the absence of the 

 entepicondylar foramen on the humerus, the presence of strong verte- 

 bral processes, and the general form of the skull. But these characters 

 are very slight in comparison to the wide differences which separate 

 the Monachinae from the Otariidae. The Otariidae are characterized 

 by the presence of an alisphenoid canal, a defective inner wall of the 

 orbit, reduced size of the tympanic bullae, basicranial region of an 

 ursid type, and an astragalus without a calcanear process. On the 

 other hand, the Phoeidae lack an alisphenoid canal, the inner wall of 

 the orbit is complete or nearly so, the tympanic bullae are usually 



175 Allen, J. A., The West Indian seal (Monachus tropiealis Gray). Bull. Am. 

 Mus. Nat. Hist., vol. 2, no. 1, p. 22. New York, 1887. 



i-sMatschie, P., Sitz.-Ber. Ges. naturf. Freunde, p. 254. Berlin, 1905. Dill, 

 H. B., and Bryan, W. A., Report of an expedition to Laysan Island in 1911. Bull. 

 No. 42, U. S. Dept. Agric, Bur. Biol. Surv., p. 9. Washington, D. 0., 1912. 



177 Gray, J. E., Catalogue of the seals and whales in the British Museum, p. 20. 

 London, 1850. Allen, J. A., Bull. Am. Mus. Nat. Hist., vol. 2, no. 1, pp. 1-2. New 

 York, 1887. 



i"s Boddaert, J., Elenchus animalium, Quadrupedia, p. 170. Rotterdam, 1785. 



