slightly to sixth; sixth segment deeply grooved 

 above. First two pleopods small and slender in 

 male, larger and definitely biramous in female; 

 remaining pleopods broad and overlapping. Uro- 

 pods with exopod broad, rounded distally; distal 

 half covered with mat of dense short hair becom- 

 ing longer on border; endopod narrow, obliquely 

 truncate, hairy at tip only. Telson with an in- 

 flated area on each side giving notched or fissured 

 appearance. 



Measurements. — Length of body: males, 95 

 mm. ; females, 92 mm. ; ovigerous females, 80 mm. 

 (Lunz, 1937b). 



Color. — Transparent gray except for porcelain 

 white chelipeds and hardened portion of carapace 

 (Lunz, 1937b). 



Habitat. — Burrows in sandy shores on or near 

 open ocean; intertidal zone to 1 fathom. 



Type locality. — Coasts of Southern States and 

 east Florida [St. Johns River]. 



Known range. — Beaufort Inlet, N.C., to eastern 

 Florida; Grand Terre Island to Timbalier Island, 

 La. 



Remarks. — For many years this species was 

 known only from a single specimen from Beau- 

 fort, N.C., and early descriptions of specimens 

 from South Carolina and Florida. The rarity of 

 occurrence in collections is due to the secretive 

 burrowing habits of the form, for it easily escapes 

 detection of the casual observer using conven- 

 tional methods of collection. (Collections can be 

 made by removing the mouth of the burrow, 

 dropping pebbles or debris down the hole, wait- 

 ing for the animal to appear at the exposed sur- 

 face, then jabbing a shovel into the sand below 

 the animal, thus cutting off escape into the bur- 

 row.) Such habits no doubt also enhance chances 

 for fossilization, for the genus is abundant in the 

 Cretaceous and Eocene of the Gulf coastal plain, 

 and somewhat less abundant in later deposits 

 down to the present time (Rathbun, 1935). 



Lunz (1937b) was the first recent student to 

 determine the habitat and abundance of the 

 species in South Carolina and his studies were 

 closely followed by those, of Willis (1942) in 

 Louisiana, and Pearse, Huram, and Wharton 

 (1942), and Pold (1946) in North Carolina. 



The animal lives in deep burrows on sandy 

 beaches that either face the open ocean or are 

 close to it. In Louisiana, the burrows occupy a 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 

 7'63-04'9 O— 65 8 



band from the intertidal zone to a distance of over 

 100 feet from shore in 5 to 6 feet of water. The 

 tubular burrows, usually vertical to the surface, 

 are divided into three portions. The mouth, about 

 5 mm. in diameter, opens into the upper portion, 

 5 to 20 cm. long and 5 to 8 mm. in diameter. From 

 this the middle portion, 10 to 15 cm. long and 

 often angled, widens gradually to approximately 

 20 mm. The third portion, 20 mm. wide, is the 

 longest. An approximate average depth of the 

 whole burrow is 146 cm. with variations from 60 

 to over 210 cm. Branches are common and arise 

 most often from the middle portion. Character- 

 istically, the burrows are lined with a brown 

 material, thinnest in the upper portion and 

 thickest (3 to 7 mm.) in the lower portion. The 

 burrows often end in an enlarged pocket lined 

 witli crushed shell, and in some the lined tube 

 extends below the pocket. 



Burrow mouths are often surrounded by fecal 

 pellets of C. major, which resist rapid disintegra- 

 tion in water. On some South Carolina beaches, 

 such pellets were washed together in patches 

 measuring up to 10 by 50 feet and piled to a 

 depth of 0.25 inch. Mouths of burrows are not 

 uniformly scattered but tend to be clumped in 

 patches or tracts, often as dense as three or four 

 openings per square foot. Chimneylike structures 

 at the mouths of burrows noted by Say have not 

 been confirmed, but a small raised ridge of sand 

 often surrounds burrow mouths. Other mouths 

 are not marked or may be located in a depression. 



In captivity, the animals burrow in sand head- 

 first with the anterior appendages until a shallow 

 pit is constructed, then the animals reverse them- 

 selves and continue to burrow tailfirst. Though 

 the shrimp do at times emerge voluntarily from 

 their burrows, such behavior is probably infre- 

 quent and may be confined to the breeding season 

 (Lunz, 1937b). The species is well fitted for a 

 fossorial life by virtue of the slender, elongate 

 body, thin exoskeleton, and flattened hairy ap- 

 pendages adapted for burrowing, carrying sand, 

 sifting food, and pumping water for feeding and 

 respiratory currents. Examination of gut con- 

 tents has shown an amorphous mass containing 

 sand grains, diatoms and other algae, and many 

 bacteria. 



Ovigerous females have been reported from 

 South Carolina in July and August, and they are 



101 



