54 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxin. 



5. CUCUMARIA CALCIGERA (Stimpson), 1851. 



1851. Pentacta calcigera Sti.mj'sox, }). (>7. 



1867. Pentacta calcigera Packaei) (cf. Whiteaves, p. 45). 



1867. Cucumaria korenii Selenka, p. 350. 



1867. Oucumaria calcigera Selenka, p. 351. 



1888. Pentacta calcigera Ganong, p. 52. 



1900. Cucumaria calcigera Ludwig, p. 146. 



1901. Cucumaria calcigera Clark, p. 162-171. 

 1901a. Cucumaria calcigera Clark, p. 492. 

 1901. Pentacta calcigera Kingsley, p. 164. 

 1901. Pentacta calcigera Whiteaves, p. 45 



(For other titles in the synonymy see Ludwig, 1900, p. 146). 



July T, 1903.— Four specimens; Station 4231; hit. 55'^ 35' 36" N. 

 long. 131^ 52' 33" W.; 82 to 113 fathoms; bottom, temperature 43.0°, 

 green mud, slate fragments, sponge, rocky. July 8. — Two specimens; 

 Station 4233; hit. 55° 54' 16" N., long. 131° 45' 58" W.; 39 to 45 fath- 

 oms; bottom, temperature, 44.7°, soft, gray mud, rocky. July 11. — 

 Eleveu specimens; Station 4246; lat. 55° 27' 57" N., long. 132° 15' 0" 

 W.; 101 to 123 fathoms; bottom, temperature 44.1°, gray, green 

 mud; coarse sand, shells. 



The following description includes an account of the stone canal, 

 perforated plates of the introvert (peristome), supporting rods of the 

 tentacles and certain features of the spicules of the body wall, which 

 up to this time have not been described. 



Form. — The body is cui'ved like a crescent tapering to both anterior 

 and posterior extremities, the latter being much more slender. Often 

 the curvature is so increased that the two ends come together. One 

 example with the tentacles completely extruded (and thus 15.5 cm. 

 long on the dorsal mid-line) shows the anterior fifth (2.8 cm.), straight, 

 of a uniform diameter (0.8 cm.) and devoid of pedicels for 2 cm. from 

 the base of the tentacles. This anterior portion is thin and flexible in 

 contradistinction to the firm, stiff main part of the body, and may be 

 called the introvert (peristome of Delage and Herouard, 190,3-4). 

 When it is retracted the apparent anterior extremity, as seen in most 

 alcoholic specimens, is as Theel, 1886 (p. 103), saj^s "more truncated" 

 than the caudal portion. 



Size. — The average measurements of the 17 specimens in the collec- 

 tion gives in centimeters: Length from the apparent anterior end of 

 the body (the introvert being retracted) to anus, along mid-dorsal line, 

 4.3, range 1.7 to 7.7; along mid-ventral line 8.42, range 3.5 to 12.7; 

 largest diameter, dorso-ventral 1.45, range 0.7 to 2.2, transverse 1.28, 

 range 0.6 to 1.7. 



Color. — White, with tints of cream color to tawny olive in certain 

 parts derived from slime which has been deposited, especiall}^ along 

 the bands of pedicels. Oral disk, clove brown. 



