488 ANATOMICAL TECHNOLOGY. 



to signify so muct of the " rima transversa cerebri magna" as has been indicated above. 

 When used for the interval between the chordm vacates, the compound term rima glottidis 

 is commonly employed. 



§ 1313. Ripa, rp.-Pl. Ill, Fig. 7 ; PI. IV, Fig. 14. 



This name was proposed by the senior author for the line formed by the rupture of the 

 endyma along the lines of its reflection from entocoelian surfaces. It is a ragged edge of 

 endyma, sometimes quite distinct, as in PI. Ill, Fig. 7. The ripa may be traced along the 

 Sulci habenarum after removal of the diatela, along the margins of the delta, along both 

 borders of the rima and on the thalamus and fornix at the nearly opposite points whence 

 the endyma is reflected upon the portiplexus. The surfaces separated by the ripa are 

 always unlike, the one being entocoelian and the other ectocoelian. 



§ 1314. Rostrum (as.), rm.— Fig. 117 ; PI. II, Fig. 4 ; PI. IV, Fig. 17. Gray, A, 623 ; 

 Quain, A, II, 538. 



The tip of the genu of the callosum. It is shorter in tlie cat than in man, and some- 

 times less extensive in naan than is commonly figured. 



§ 1315. Septum lucidum (cerebri), {az.), Spt. lu. — Fig. 113. 



8yn. — Septum pellucidum, speculum, mediastinum s. diaphragma ventriculorum later- 

 alium. 



This consists of two lateral halves, the hemisej^ta. Each hemiseptum is so much of 

 the mesal wall of the procoelia as is intercepted by the callosum and the fornix when the 

 two apposed surfaces of the hemispheres are united. In man, although a space, the^&^M- 

 doccelia, remains between them or is formed by absorption, the compound septum so con- 

 stituted is so thin as to have received the name lucidum. In the cat and in most other 

 mammals, the adjective is wholly inapplicable. See hemiseptum (§ 1241) and Area sep- 

 talii (§ 1203). 



§ 1316. Splenium {az), sp.—F\g. 114, 115, 117 ; PI. II, Fig. 4 ; PI. Ill, Fig. 6 ; PI. IV, 

 Fig. 14, 17 ; §§ 1131, 1195, 1238. 



The rounded caudal border of the callosum. When the caudal portions of the hemi- 

 spheres are separated, the splenium appears as a thick white band. Its fibers pass laterad 

 into the caudal portions of the hemispheres. Its ventral surface is continuous with the 

 lyra. 



The term is in common use, but we have not found it in the works of Gray or Quain. 



§ 1317. Stria longitudinalis (callosi), Str. Inj.—Fig. 115 (?). Gray, A, 624 ; Quain. 

 A, II, 537. 



Syn. — Stria Lancisi, nervus Lancisi. 



The human callosum is described as presenting several more or less distinct longitudi- 

 nal lines. We have not satisfactorily observe! tliem upon the fresh brain of either man or 

 the cat, but presume they are represented by the longitudinal striation vaguely shown in 

 Fig. 115. 



§ 1318. Striatum (Corpus), s.— Fi<?. 113 ; PI. Ill, Fig. 13 ; PI. IV, Fig. 15, 16 ; §g 1131 

 (14), 1149. Gray, A, 625 ; Quain, A, II, 547, 564 



Syn. — Nucleus caudatus, eminentia lenticularis, ganglion cerebri antcrius, apex cruris 

 medulliB oblongatae. 



As indicated by the above synonymy, the corpus striatum of the older anatomists 

 included the entocoelian ("intraventricular") portion, which appears in the procoelia (PI. 

 IV, Fig. 16), and the ectocoelian (" extraventricular") porti(m, which is commonly de- 

 scribed as imbedded in the wall of the hemisphere. The former is specified as Nucleus 

 caudatus and the latter as Nucleus lenticularis. In man, between the two is a mass of 



