190 CHAETODERMA. 



developed digestive gland. Copulatory apparatus lacking. Coelomoducts 

 remain separate. Cuticle thin, spicules flat, often needle-form, but solid. 

 Inhabit bottom ooze. 



CHAETODERMA Loven, 1845. 



Body vermiform, without ventral groove; mouth and anal chamber ter- 

 minal. Two gills. Sexes separate. Radula reduced to conical peg. Type 

 of genus 

 C. nitidulum Loven. 



Head, cylindrical or pear-shaped, bounded posteriorly by a circular groove. 

 Spines with keel absent or but sUghtly developed. North Atlantic (p. 193). 



C. caudatum, .sp. nov. 



Length from 3.3 mm. to 7.75 by 1.3 mm. greatest diameter. Greatest 

 thickness of body in preabdomen; the postabdominal region narrows abruptly 

 to a tail-hke appendage. Northeast coast of the United States at a depth 

 of 428-499 fathoms, (p. 193). 

 C. vadorum, sp. nov. 



Length 12.5 mm. by 1.1 thickness of preabdomen to 15.2 by 1.45 mm. 

 Spines strongly keeled and at junction of metathorax and abdomen measure 

 from 0.1 to 0.14 mm. in length. Mouth occupies a cleft in the buccal plate. 

 Off coast of Maine at a depth of 25-95 fathoms, (p. 195). 

 C. lucidum, sp. nov. 



Body size variable, ranging from 1.2 mm. width by 11.25 length to 0.75 

 mm. mdth by 25 mm. length. Spines with keel sUght or undeveloped, with 

 average length on preabdomen of 0.12 mm. Mouth occupies a cleft in the 

 buccal plate. Off coast of New Jersey at 428^79 fathoms depth, (p. 198). 



C. bacillum, sp. nov. 



Length 11-17 mm. length by 0.9-1.07 mm. greatest diameter. Spines 

 moderately keeled with a length of 0.11-0.16 mm. at the junction of the pro- 

 and metathorax. Mouth perforates the buccal plate. Off the Massachusetts 

 coast at a depth of 900 fathoms, (p. 201). 

 C. squataosum, sp. nov. 



Length 25.7 mm. length by 1.3 mm. greatest thickness. Mouth pierces 

 the buccal plate. Spines unusually thin, weakly keeled. Off Massachusetts 

 at 1,234 fathoms depth, (p. 204). 



