ZOOLOGICAL SOCIETY BULLETIN 85 
Like most small tropical fishes, they prefer a 
diet of raw meat, live worms and crustaceans, 
but will take other foods on occasion. 
Cross-breeding of Helleri with other fishes 
has been tried with much success and the oftf- 
spring are not always sterile, though they have 
the reputation of being shorter lived than the 
pure stock. 
The Red Helleri, which brings high prices and 
the exact parentage of which has not been re- 
yealed by its producers, is acknowledged to be a 
hybrid. Crosses between X. helleri and Platy- 
poecilus rubra have been frequently made, and 
the Helleri has also been crossed with the rain- 
bow fish. Handsome hybrids are produced by 
crossing X. helleri with P. pulchra, the offspring 
being beautiful black fishes with sides of burn- 
ished blue and green satin. 
PLATYPOECILIDA 
The Platypoecilida come from South America 
and Mexico, and are commonly called by their 
specific names of maculata, rubra, pulchra, etc. 
All are viviparous, and the female, kept quite 
alone, may surprise her owner after producing 
one family, by giving birth to another when a 
number of weeks have elapsed. A female rubra 
at the Aquarium gave birth to eighteen young 
in two days. 
The delicate, blue-tinted Platypoecilus macu- 
latus from Central America and Mexico, in which 
the female’s anal fins are edged with black, is 
most timid; and the P. rubra, with its scarlet 
color and occasional black specks and green- 
tinted scales, the most handsome. The male 
rubra is about half the size of the female and 
more brilliantly colored. Both sexes have a 
black spot at the root of the tail. In the color- 
ing of P. pulchra a rich, satiny black predom- 
inates. 
All are partial to raw meat and live crusta- 
ceans, but most will take prepared foods by 
oway of variety, and they are always hungry. 
If the aquarium is covered with a strip of 
glass during all but the warm months of sum- 
mer, artificial heating of the water is unneces- 
sary, a room-temperature of 68 degrees being en- 
tirely suitable. 
Hap.Locui.us 
Half a dozen species of Haplochilus have 
been introduced into the United States and have 
found popularity because of their attractive 
shapes and colors, beautiful fins and tails being 
a common characteristic of the males. All are 
egg-layers, and all prefer live food though they 
will take other foods, even the dried kinds. The 
eggs are adhesive and are laid among the aquatic 
plants, where they hatch in from ten to fourteen 
days. It is well to remove the adults to another 
tank after they have spawned; also to watch 
and sort the young so that the larger may not 
feast upon the smaller. Young and old may be 
ted the same as goldfishes. 
Some of these fishes come from Africa, others 
trom India. Among the former are H. spil- 
argyreus with six black vertical bands and a 
red and yellow spot on the gill cover, and the 
allied H. chaperi, similarly banded and measur- 
ing about two and a half inches. The _best- 
known haplochilus of all comes also from Africa 
and is one of the smallest of the species, attain- 
ing but two inches in length. It is called the 
Ribbon-tailed Haplochilus (H. cameronensis), 
and the beautiful tail, shaped like a lyre in 
the male, adds to the attractiveness of a delicate 
body of blue, spotted with rows of scarlet, and 
red-striped fins. 
From India comes the Red-spotted Haplo- 
chilus (H. lineatus), the male having green and 
blue sides, his body and fins spotted with scarlet, 
his tail bordered with red, black and white, the 
female having a black stripe from head to tail. 
This species has been kept for two years at 
the Aquarium, and is the largest of the group, 
attaining four and a balf inches in length. Other 
species from India are H. fasciolatus in which 
the female is smaller than the male, and the 
male’s yellow-blue body is dotted with seven 
rows of scarlet specks, his tail being enhanced 
by two long central rays; the H. panchaz, of 
which several varieties are known, also called 
the Red-tailed Haplochilus which attains a 
length of three inches, has bluish sides and in 
the male a tail bordered with red and_ black, 
in the female with red only. | 
Rivutus 
Several species of the hardy Rivulus are im- 
ported from Brazil and Central America, R. 
poeyit being perhaps the commonest, the entire 
length of its plain, fish-gray body offset with 
rows of scarlet and the fins with yellow and red. 
As in many small fishes, the fins of the male 
are more highly developed and colored than 
those of the female. The body and fins of R. 
flabellicauda are similarly dotted and marked 
with red, and it has a red throat. The Golden 
rivulus is a variety of R. Poeyi, the dots and 
markings of scarlet being the same but the body 
color being golden instead of gray. The average 
length of Rivulus is about three inches. 
Rivulus are noted for their capacity for jump- 
ing out of the water. They will lie for hours 
