483 ANATOMICAL TECHNOLOGY. 



to signify so much of the " rima tranmersa cerebri magna" as has been indicated above. 

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

 is commonly employed. 



1813. Ripa, rp. PI. 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 uulike, the one being entocrelian and the other ectocoelian. 



1314. Rostrum (az.\ rm. Fig. 117 ; PI. H, Fig. 4 ; PI. IV, Fig. 17. Gray, A, 623 ; 

 Quain, A, II, 538. 



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

 times less extensive in man than is commonly figured. . 



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



Syn. Septum pellucidum, speculum, mediastinum . diaphragma ventriculorum later- 

 alium. 



This consists of two lateral halves, the Jiemisepta. Each hemiseptnm is so much of 

 the mesa! wall of the procoslia as is intercepted by the callosum and the ibrnix when the 

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

 doccdia, 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 Jiemiseptum ( 1241) and Area sep- 

 talig (% 1203). 



1316. Splenium (az\ sp. Fig. 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), 8tr. Ing. Fig. 115 (?). Gray, A, 624 ; Quain, 

 A, II, 537. 



Syn. Stria Lancisi, nervus Lancisi. 



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

 nal lines. We have not satisfactorily observed them 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. Fig. 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 anterius, apex cruris 

 medullae oblongatae. 



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

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

 IV, Fig. 16), and the ectoco3lian (" extraventricular") portion, 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 



