
MARINE AQUARIA 

Pentacta frondosa, (Jaeg.), or Brown-Sea-cucumber 1s the largest com- 
mon Atlantic species which measures from a few inches to a foot in length 
when extended. AHolothuria princeps and H. floridana, the Florida Sea- 
cucumbers, are large species which have been collected and dried for 
export to China. 
FEATHER STARS AND SToneE Livies. This class of Crinoidea inhabit 
deep water where they form branching featherlike and flowerlike beds. 
Some are permanently attached, others become detached and float about 
by movements of the raylike arms. They are rarely found on the shore 
and fail to survive in aquaria. | 
Crustaceans. The larger Marine crustaceans are divided into a 
number of groups, the Branchyura or true Crabs, the Anomoura or Her- 
mit Crabs, etc., the Macroura or Lobsters and Shrimps, the Xiphosura or 
King Crabs, the Squillide or Mantis Shrimp, the Cirripedia or Barnacles 
and Tops; and the smaller Marine Entomostraca or Water Fleas. 
These will be mentioned in this order. 
Callinectes hastatus, (Ord.), or Common Edible Crab, Blue Crab, 
Sea Crab, has the shell or carapace about twice as broad as long, and 
armed with a distinct projecting spine and eight short acute teeth on each 
side, gradually increasing in size towards the eyes. here are four un- 
equal-sided teeth between the eyes and a median spine beneath. The 
front limbs, bearing the claws, are similar to each other in form, and the 
three succeeding pairs of legs are slender, terminating in sharp points, and 
the posterior pair end in expanded oval joints for swimming. ‘The cara- 
pace grows to a length of 3 inches and a breath of 51% to 6 inches, and is 
covered with minute granulations and margined with fine hairs. The 
upper surface is of dark-green or bluish color, the lower dusky-white, the 
feet and claws blue, tipped with yellowish-red. The period of spawning 
and shedding extends over several months. It is very active, crawling and 
swimming rapidly, and may be taken on muddy and sandy bottoms in 
both salt and blackish water, from Cade Cod to Florida. It is predace- 
ous and feeds upon all living and dead animals. This species may be 
distinguished by the sharp spine on each side of the carapace. ‘There are 
four other species of this genus in more southern waters. 
Carcinus menus, (Say), or Green Crab, has a bright green color varied 
with spots and blotches of dull yellow and brown, and has the carapace and 
limbs more or less granulated. It has heavy claws and legs shorter than 
the foregoing and shorter spines at the sides of the narrower carapace, with 
four unevenly cirrated teeth at each side and three between theeyes. The 
last pair of legs also nearly resemble the other three pairs and lack the 
broad swimming blades of the foregoing species. Abundant between tide- 
3°97 
