ting edge with large rectangular tooth fitting 

 into pit on immovable finger when closed; im- 

 movable finger with distinct tooth at inner margin 

 of pit; palm swollen, tuberculate at base and on 

 base of fingers, tubercles on proximal lower part 

 of palm arranged in rows or honeycomb pattern; 

 carpus smooth, short, cup-shaped; merus about 

 one-third length of palm. Smaller second leg 

 much as larger one in general shape; palm some- 

 what swollen, with scattered tubercles anteriorly. 

 Third leg with greater part of propodus reaching 

 beyond tip of antennal scale; dactyl short, broad, 

 bifurcate. 



Abdomen smooth ; pleura of first five segments 

 broadly rounded; sixth segment half length of 

 telson. Telson with two pairs of dorsal spines 

 somewhat removed from lateral margin, anterior 

 pair close to anterior margin, posterior pair 

 slightly behind midlength; posterior margin with 

 three pairs of spines, outer pair short and located 

 in advance of larger intermediate and inner pairs. 

 Uropods broadly ovate, outer margin of exopod 

 ending in a tooth flanked medially by a movable 

 spine. 



Measurements. — Length of body : male, 20 mm. ; 

 ovigerous females, 16 to 20 mm. 



Variations. — Juveniles may have a shorter ros- 

 trum with fewer dorsal teeth, and in some speci- 

 mens the second chelae may be smooth. 



Color. — Clear, milky white; integument so 

 transparent that color of internal organs is plainly 

 visible; egg masses light bluish green. 



Habitat. — This species is known to live in 

 sponges in coastal waters in company with 

 Synalpheus longicarpus and S. toivn-sendi; 10^0 

 fathoms. 



Type locality. — Fishing grounds, 20 miles off 

 Beaufort Inlet, N.C. 



Known range. — Off Beaufort, N.C. ; off Logger- 

 head Key, near Tortugas, and Franklin County, 

 Fla. 



Remarks. — Ovigerous females have been re- 

 ported from Florida in July and North Carolina 

 in August. Gurney and Lebour (1941) described 

 the last larval stage of a shrimp doubtfully re- 

 ferred to P. wilsoni. 



When disturbed, the animals are able to make 

 a snapping sound with the large chela quite as 

 loud as that made by one of the true snapping 

 shrimps. 



Genus Pontonia Latreille, 1829 



Holthuie, 1951a. p. 115.— Hemming, 1958b, p. 124. 



Pontonia domestica Gibbes 



Figure 39 



Pontonia domestica Gibbes, 1850, p. 196. — Holthuls, 1951a, 

 p. 122, pi. 38, figs, a-j (rev.). 



Recognition characters. — Rostrum depressed, 

 rather narrowly triangular, decurved ; reaching to 

 second article of antennular peduncle; tip acute 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



Figure 39. — Pontonia domestica Gibbes. A, anterior part 

 of body in dorsal view, X 5.5 ; B, antennule, X 7.5 ; C, 

 antennal scale, X 7.5; D, first leg. X 5.5; E, larger 

 second leg, X 2.5 ; F, smaller second leg, X 2.5 ; G, third 

 leg, X 5.5; H, dactyl of third leg, X 20; I, telson in 

 dorsal view, X 9.1 (after Holthuis, 1951a). 



47 



