242 Bulletin American Museum of Natural History. [Vol. XXVII, 



Shull. — The general proportions of the young skull are much less dolicho- 

 cephalic than in the adult and in so far approach the mesaticephalic propor- 

 tions of the embryonic Centetes (Parker/ 188G, pi. 32). The basifacial and 

 basicranial axes make only a very slight angle with each other. 



The nasals in the young skull (Amer. ]\Ius. No. 28272) are still suturally 

 distinct in the mid line, as in the embryo Cenfetes, but in the adults the 

 opposite nasals haVe completely coalesced, although the position of the 

 suture is indicated by a groove. The frontals in the young skull send 

 forward two large V-shaped extensions which are broader than those in the 

 young Centetes. In the adult Solenodons these Vs are completely coalesced 

 with the nasals, Init the anterior limits of the temporal muscles make it a{)pear 

 falsely as if the naso- frontal sutures were above the orbits and as if the nasals 

 broadened proximally after the jNIarsupial fashion. 



In the top view the skull, even of the old individuals, differs from that 

 of Snlenodo)! cuIhuius in the feebleness of the interorhital constriction, the 

 middle portion of the skull being almost cylindrical as in the other Zalambo- 

 donts. The interorhital constriction in »S. cuhanus is one of the features 

 emphasized by Dobson (1883, p. 87) as serving to separate the Solenodonti- 

 dae from the other Zalambdodonts, but it is seen to be due on the one hand to 

 the broadening of the brain case and on the other to the primitive breadth 

 of the frontal region above the large olfactory scrolls of the ethmoids; and 

 is accordingly merely a primitive mammalian character and a very insuffi- 

 cient indication of near affinities with Myogale. 



The young Solenodon skull possesses a pair of good sized interparietal 

 bones (Fig. 18, A^, Ip.) separated by a median but slightly asymmetrical 

 suture, and partly overlaid by the parietals. 



The interparietal appears in jNIarsupials, Rodents, Orijcteropus and many 

 other orders (Weber, 1904, p. 50) and usually fuses with one or another of the 

 adjacent bones. In many forms it arises from paired ossific centres so that 

 the young Solenodon is very primitive in this respect. A large, apparently 

 unpaired, interparietal appears in the foetal and young Erinaceus, Centetes, 

 Hemicentetes and Microgale (cf. Parker, 1886, pll. 33-35). 



The laclm/mal in Solenodon, as in Erinaceus, is a small narrow bone 

 placed well up on the side of the face and pointing obliquely upward and 

 backward as in Centetes, but it is smaller than in that genus (contrast the 

 large lachrymal of Marsupials). As in Centetes and Hemicentetes the 

 lachrymal foramen is marginal and is bounded antero-inferiorly by the malar 

 ridge of the maxillary. The ma.xiUary extends well up on the inner side 



1 Statements in regard to the young and embryonic Erinaceus, Talpa, Sorex, Centetes, 

 Hemicentetes, Microgale, Rhynchocyon, in the following description are based on Parker's figures 

 (1886, pll. 20-36). 



