This month you'll receive a little black and white set of 4" pot sized plants
Senecio haworthii (also called Caputia tomentosa) is the "white" and does best with very gritty soil with some coarse sand added. Be VERY careful with water during summer dormancy. Does well in bright light to full sun. Bottom watering helps prevent overwatering. This plant is native to South Africa so arid conditions are its norm.
The "black" this month is an echeveria ehoc which is a very dark brown nearly black. It's similar to echeveria Black Prince but seems to be a hardier specimen. This echeveria needs full sun for best coloring. Water similarly as other echeverias.