54. AMERICAN SPIDERS AND THETR SPINNINGWORK. 
blunt head of the larva was too large to make an attachment. When full 
fed the larva was about three-eighths of an inch long, and had fourteen 
segments, counting the head as one. ‘The cocoon was shuttle shaped, 
whitish and thin, the spider’s original web forming its suspending cords; 
the movements of the larva and pupa were perceptible through the cocoon. 
The perfect fly appeared on the 12th of June, and proved to be a female 
of Polysphincta tuberosa Gravenhorst. 
VIL. 
Mr. John L. Curtis,! of Oakland, California, has written me an inter- 
esting account of a new body parasite taken upon a species of Theridioid 
spider, Labulla inconstans,? 
The spider is quite 
common in the re- 
gion surrounding 
San Francisco, and domiciles 
in large leaves, the edges and 
ends of which it bends downward, and 
fastens with a sheet of web composed of 
many white threads spun across from side 
to side. The cocoon, which is round and 
white, is woven within this maze, and is 
jealously watched by the mother, a small 
spider of a light gray color, with pinkish 
tints on the legs and a tinge of yellow on 
the abdomen. 
Body Par- 
asite. 
41. 
Fig. 41. Parasite cocoon in site, natural size. 
Fig, 42. The same, enlarged greatly. Fic. On July 13th (1890) a specimen was 
43. The pupa. 
found upon whose abdomen was fixed a 
large yellow larva. By the 15th the larva had entirely consumed the spider 
and spun itself into its cocoon. (Figs. 41, 42, 48.) On the 17th it changed 
to chrysalis, and on the 27th of the month hatched. ‘The cocoon is a cylin- 
drical case of loose fibres, and hung suspended, head downward, upon lines 
stretched within the bottle wherein it was bred. Mr. HE. 'T. Cresson, of Phila- 
delphia, has identified the parasite insect thus hatched as a probably new 
species of Polysphincta, a genus of Pimplinew, a subfamily of the great 
family Ichneumonide. It is obvious that in order to deposit her egg upon 
the body of the spider, this mother Ichneumonid must have successfully 
threaded the labyrinth of intercrossed lines and obtained a favorable posi- 
tion underneath the abdomen. A delicate piece of aranead scouting this! 
Y 
1T regret to record the death of this promising young naturalist since writing this note. 
Though an incurable invalid he was an enthusiastic loyer of araneology, and had already 
done some good work therein. 
2 Dr. George Marx thus determines the genus, and the specific name is that suggested 
by Mr. Curtis. 
