200 



Charles Searing Mead. 



on the roof of the capsules, there extends a well developed furrow, 

 the sulcus supraseptalis (Fig. 9). In many animals with a freely 

 movable snout (Erinaceus, l^asua, Talj)a) this furrow lodges the 

 ligamentum suspensorium (Spurgat), which extends forward from 

 the region at the anterior end of the suture between the nasal bones. 

 I can find no mention in the literature of such a ligament having 

 been found in Sus, either in adults or in embryos, but my series 



Fig. 9. Section showing Jacobson's organ J.o. and the naso-palatine duct 

 d.n.p. X 10. 



J.c, Jacobson's cartilage; d.n.l., ductus naso-lacrymalis ; m.t., maxilloturbin- 

 al ; n.s., nasal septum ; r.l.s., anterior end of the recessus laterale superior ; 

 peri., periosteum which forms the maxillary bone ; s.sup., sulcus supraseptalis. 



of sections shows this ligament extending forward from the region, 

 where the anterior ends of the nasal bones are later located to the 

 point where the prenasal bone is developed. Throughout its whole 

 length the sulcus supraseptalis lodges a blood-vessel deep in its fur- 

 row. Anteriorly this vessel lies beneath the ligamentum sus- 

 pensorium. In some embryos (Macacus, Semnopithecus, Tarsius, 

 Talpa) the sulcus is only present in the anterior, part of the tectum 

 nasi, while in others (Homo, Lepus, Bos, Sus) it extends throughout 



