. 
Dr. Engelmann on the Cereus giganteus of California. 3 
Upwards, the number of ribs increases by bifurcation, or addi- 
tional ribs originate in the intervals. There the ribs are “ sharply 
Won : 
0 
inch distant from another. Radiate spines }—? inch long; central 
Spines stouter and longer; the lowest deflexed AB inches long, 
he two next esti’ not three upper ones pointing upwards an 
oti wakdls and s 
Dr. Parry was i le that the flowers were bad 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 og Stee fs 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. 
he 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 bears no hair-like spines, and no cephalium, 
or distinct woolly head, and that the fruits are (as is said) spinu- 
ese and not scaly. It i is by far the largest Cereus known; and 
only some Pilocerei approach it in size. 
The only Cactacee thus far known to grow in California were 
those vaguely noticed by Humboldt (the “ Organos del tS 
and some Opuntiz); the Achinocactus virtdescens and Cer 
Californicus discovered by Nuttall in 1834; the Cacti aiid % és 
the Gila by Col. Emory in the fall of 1846 and mentioned in his 
report; Mamillaria Goodrichti, lately described by Scheer, of 
Kew, and E'chinocactus Californicus of Monville. 
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, 
from the sea-coast to the mouth of the Gila. e, 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. 
I subjoin here a short memorandum of Dr. Parry’s Californian 
Cactacee, reserving a fuller description for a more extended me- 
oir. 
Manreiarra TETRANCISTRA, N. Sp.: subglobosa ; aculeis radi- 
aiibis brevibus albis numerosis, centralibus 4 longioribns eruci- 
Mist uneinatis ; floribus centralibus parvulis Monti oh stig- 
