ry 
Dr. Engelmann on the Cereus giganteus of California. 337 
Upwards, the number of ribs increases by bifurcation, or addi- 
tional ribs originate in the intervals. 'Theresthe ribs are ‘“ sharp 
rounded,” 14 inch wide, with deep intervais, 24 inches wide, 
densely set with spines. Areola somewhat elevated, circular, one 
inch distant from another. Radiate spines 4-3 inch long ; central 
spines stouter aud longer; the lowest deflexed, 3-23 inches long, 
the two next lateral,.the three upper ones pointing upwards and 
outwards, and shorter. 
Dr. Parry was informed that the flowers were produced in May 
and June, from the summit of stem and branches; they are said 
to be white, with a red centre, and three inches in diameter. The 
fruit matures in August, and is set with small spines: it is obo- 
vate, one and a half inches in diameter, red, pulpy, of sweet taste. 
The seeds‘ obtained by Col. Emory and by Dr. LeConte have 
already been noticed in Emory’s Report; they are 0°7 lines long, 
obovate, obliquely truncate at base, black, smooth, shining. Em- 
bryo hooked, without an albumen; cotyledons foliaceous, une- 
qual, incumbent. ; . 
My opinion that our plant is a true Cereus and not a Pilocereus, 
which was based on the structure of the seeds (the foliaceous, 
not globose cotyledons), appears to be further confirmed by the 
fact that this Cactus hears no hair-like spines, and no cephalium, 
r distinct woolly head, and that the fruits are (as is said) spinu- 
lése and not scaly. It is by far the largest Cereus known; and 
only some Pélocerei approach it in size. 
Dr. Parry has in the years 1849 and 1850, when he was also 
attached to Col. Emory’s corps in the survey of the Mexican 
boundary, examined and described ten or eleven distinct species 
of Cactacez, all found along the southern boundary of California, 
rom the sea-coast to the mouth of the Gila. He, as well as Dr. 
LeConte, states that much farther to the north no species of this 
family are found, except an Opuntia, cultivated and now natural- 
ized abont the missions. og ROE 
J subjoin here a short memorandum of Dr. Parry’s Californian 
Cactaceze, reserving a fuller description for a more extended me- 
moir. 
“1. Mawttcarra TeTrancisTRa, n. sp.: subglobosa ; aculeis radi- 
alibus brevibus albis numerosis, centralibus 4 longioribus cruci- 
atis uncinatis; floribus centralibus parvulis flavido-rubellis ; stig- 
