504 THE AMERICAN NATURALIST. | [Vor. XXXIV. 
The Calappa lives usually on sandy shores, into which it is in 
the habit of burrowing. 
Of the Matutidz, which are sparsely represented in North 
America, the species of Hepatus are large and strikingly 
colored. They differ from Calappa in the smaller claws and 
in the narrower posterior portion of the shell. Hepatus ephelt- 
ticus is known on the Gulf coast as ** Dolly Varden.” 
The Leucosiide are generally distinguished by their globular 
carapace, long claws, and comparatively small walking feet. 
The largest and most conspicuous North-American species are 
the Persephona punctata, or “speckled spider,” of the Atlantic 
and Gulf coasts, and ARazda/Ea ornata of the Pacific coast. 
The Dorippidz are marked by the reduction of the last two 
pairs of feet, which are raised on the dorsal surface of the 
carapace. The first two pairs of walking legs are long, ena- 
bling the crab to run fast. 
In the key which follows, the same terms are used to indicate 
distribution as in No. VII of these synopses; and, as in that 
number, many of the definitions have been taken from the 
works of Drs. Stebbing and Alcock. 
TRIBE OXYRHYNCHA, OR MAIOIDEA. 
Carapace narrowed anteriorly and rostrate, with the hepatic regions 
small, the branchial large. Epistome generally large. Buccal frame 
quadrate, with anterior margin straight. Nine pairs of branchiz, with the 
efferent channels opening at the sides of the endostome. The afferent 
channels open behind the pterygostomian regions, in front of the bases of 
the chelipeds. First antenne longitudinally folded. Third maxillipeds 
with the fifth joint articulated at the apex or at the front inner angle of the 
fourth. The genital organs of the male are inserted at the bases of the 
last pair of trunk legs. 
KEY TO THE FAMILIES OF THE TRIBE OXYRHYNCHA. 
A. Basal joint of antennz well developed. Chelipeds not a great deal 
longer than the other legs. . ;. Mari; Leach 
A’, Basal joint of antenna very shall, and deabedded between the front 
and the floor of the orbit. Chelipeds a great deal longer and more 
massive than the other legs : 
PARTHENOPID;E Milne-Edwards, White 
