386 SURG. J. GC. THOMPSON ON THE 
23,25. The right lung has a large free apex. ‘There is no trace: 
of the left lung. 
The external landmarks of the principal viscera in terms of 
gastrosteges are as follows :— 
GastLOsteses) Wesens.c cudnt ee a0 140 100 per cent. 
IFlicai Grameen in aici el Cao oa. 30 21°4 
UG Ive rem DU meetce eet hese. ote tcins 40 28°6 
ny (EN 00 ba ak Bn a 66 42°8 
Gall-bladder. 2.01.02. .s2sne:sn2c22 75 53:6 
Kidweyarieht, tip 2...t2.c0c--2- 98 67:2 
Hi see MOIMGEsc et) teats as 0 120 85:7 
*, lefitstioy tenes seeeeee IAL 19°2 
4; s/s CUNCS etc tera er 128 ies} 
The number of scale-rows, the sequence in which they are 
suppressed, and the gastrostege level at which they terminate 
are as follows :— 
19 rows, IV row ends, right 68th, left 71st gastrostege, leaving: 
17 99 Vi 99 99 Pie] 81st, bP) 81st 9 27 
15 which are continued to the vent. 
99 
ZAMENIS ConstTRiIcToR Linnzus. 
Specimen.—_U.S. National Museum No. 504301. Sausalito 
Peninsula, California. Aduit female. 
The tracheal membrane begins at the glottis and extends along 
the left quadrant of the tube. It is bare anteriorly but beconies 
lined with respiratory tissue at the 15th g.; at first the air-cells 
are large and shallow, further on assuming the type of those in 
the lung. The trachea enters the lung at the 34th g.; a few 
millimetres posterior to the rudimentary lung it tapers to a 
narrow fibrous intrapulmonary band, less than 1 mm. wide, 
which continues along the ventral wall of the lung to the 
anangious part. The intercartilaginous fibrous portion of the 
trachea is pigmented a dark grey, which is in sharp contrast to 
the white of the cartilages and gives the trachea a regularly 
banded appearance. There is a free apex 5 mm. long, closely 
bound to the right side of the trachea, and with two small 
openings into the lung. The right lung is lined with alveoli to 
the 54th g., where they cease rather abruptly and the lung 
becomes anangious. The left lung, 2°5 mm. long, is at the 
36th g.; it is lined with air-cells and opens into the trachea. 
The vertebral artery courses superficially over seven gastro- 
steges; it arises from the right aortic arch at the 30th g. and 
enters in the median line at the 23rd g._ It gives off two inter- 
costal branches: I.-28, I1.-26, and two minute twigs to the 
esophagus: I.-27, I1.-25. In another specimen (No. 504043,. 
same locality and sex) having the same number of gastrosteges 
and with the heart at the same level, this artery courses over 
nine gastrosteges and gives off six intercostal branches: L-28 ; 
