1913.] Clark, Echinodcrms from Lower California. 231 



Laetmenoecus scotoeides L sp. nov. 



Body nearly cylindrical, or perhaps somewhat flattened on ventral surface, 

 larger posteriorly than anteriorly, 150-200 mm. long, 25-35 mm. in diameter. Along 

 each side of the body, delimiting the ventral surface, which becomes distinctly nar- 

 rower posteriorly, is a series of sixteen or seventeen large papilla-like pedicels. There 

 appear to be no other ambulacral appendages anywhere on the body, unless there are 

 a few scattered pedicels along the mid-ventral ambulacrum near the rear of the ani- 

 mal. I was unable to make myself certain on this point nor could I convince myself 

 beyond question that there are no dorsal appendages in the living animal. However 

 I could find no satisfactory evidence of their present or past existence. Body wall 

 thin and soft, but completely full of the calcareous particles; even the longitudinal 

 muscles are full of calcareous rods. Tentacles fifteen, of equal size; the terminal 

 disk is 3-5 mm. across. Anus terminal or slightly dorsal in position. Calcareous 

 ring well developed, very much like that figured by Theel for Lcetmogone wyville- 

 thomsoni. Polian vessel, single and large. Madreporic openings in back, about 

 35 mm. from anterior end, not at all conspicuous. No evident genital papilla. 

 Genital glands in two short tufts, one on each side of mesentery, much like those 

 figured by Theel for Lcetmogone. Calcareous particles consist of wheels and rods. 

 The former are similar to those of Loetmogone and need no detailed description; the 

 small ones are .09 mm. in diameter or less and have ten to thirteen spokes; the large 

 ones are .15-.20 mm. across and commonly have ten spokes. The wheels are chiefly 

 found on the dorsal surface but small ones also occur in the ventral integument. 

 The rods are nearly straight and only slightly roughened bodies, .15-. 25 of a milli- 

 meter long; they are abundant ventrally but are few and far between dorsally; they 

 are common in the longitudinal muscles. Color uniform deep purple. 



Type. Cat. No. - -, U. S. N. M., from Station 5685. 



If the above described specimens had any obvious appendages on the 

 dorsal surface, they would fit well into the genus Lxtmoyone, but there are 

 no such outgrowths, nor is there any evidence to indicate that they were 

 present in life and have been accidentally lost. In one specimen, I found 

 what seemed to be two pedicels in the midventral line posteriorly, but the 

 conditions of preservation prevented my determining the point satisfactorily. 

 Under the circumstances, I cannot place these specimens in Lcetmogone 

 and so have instituted a new genus for them. 



Station 5685. Southwest from Ballenas Bay, west coast of Lower 

 California, 645 fms. Three specimens. 



Laetmophasma fecundum. 



Ludwig, 1894. Mem. M. C. Z., Vol. 17, p. 85. 



These specimens are much smaller than Ludwig's types, measuring 

 only about 85 mm. in length, and I am far from feeling satisfied as to their 



1 aKOToti.5r)s = dark-looking. 



