384 SURG. J. C. THOMPSON ON THE 
The external landmarks of the principal viscera in terms of 
gastrosteges are as follows :— 
Gastroste ces mentees. versus 157 100 per cent. 
Hearst apexursatce tesa. chiag 26 16°8 
TA Viers MUN waeme ce oc aio hibe «tite ay 30 22°3 
said ROI Gren ete oc uaiiehcssnes 70 44-6 
UE eval IOie) ga Redanedlopeoonbeosr 86 54:8 
IKercliveneiacle iii bl) pasate eee Sela 73°8 
a BN CAG GUE tiie en aeRO 139 88°6 
Pee We Lbs CLD seers lia acs 125 79°6 
- gt OW et emen ce Sok 145 92:3 
The number of scale-rows on the body, the sequence in which 
they are added and suppressed, and the gastrostege level at which 
these changes occur may be thus presented :— 
Neck. 
21 rows, IV row ends, right 8th, left 7th gastrostege, leaving : 
Body. 
19 rows, V row added, right 26th, left 24th gastrostege, making: 
2 aoe A Ba LUC IS gm COA Drove ‘6 leaving : 
Tg centile Vo Manet Usa Be Sihdae, ” Go SOila 
17 +4, ~+~which are continued to the vent. 
99 39 
An inspection of this table will show that on the body the 
scale-row count is raised from 19-21 rows at about the level 
of the base of the heart, and that this maximum number of rows 
continues to the posterior end of the liver, where the original 
count of 19 rows is resumed. A further tapering of the body is 
indicated by the reduction of the 19 rows to 17, and this occurs 
just posterior to the gall-bladder. The relation existing between 
the position of the viscera and the added and suppressed scale- 
rows has been studied in fifty specimens of this species. The 
example just recorded offers the normal condition for individuals 
inhabiting the Sausalito Peninsula. 
TROPIDONOTUS VIBAKARI Bole. 
The salient character of this species is the peculiar type of 
intromittent organ. This has warranted the removal of the 
species from Z'ropidonotus and the establishment of a new genus 
Hebius*. 
Specimen.—California Acad. Sci. No. 15861. Yokohama, 
Japan. Adult female: total length 644, tail 140 mm. 
The trachea ceases abruptly at a point just posterior to the 
apex of the heart. The tracheal membrane begins at the glottis 
and extends along the right side of the tube; from the origin 
to the 15th g. it is finely plicate; it then becomes lined with 
respiratory tissue, the alveoli being at first very shallow and 
indistinct ; at the level of the auriculo-ventricular septum the 
* Thompson, P. Z, 8. 1913, p. 424. 
