353 [VerrlU. 



dor, Dr. A. S. Packard, Jr. On this coast, hitherto only found thrown 

 upon the beaches by the waves. Dr. Packard's specimens were 

 dredged in fifteen fathoms, sandy bottom. 



Pentacta minuta (Fabr. sp.) 



Cucumaria minuta Liitken, op. cit. p. 7. Ocnus Af/resii Stimpson, 

 Inv. p. 16, 1853. 



Grand Menan in twenty-five fiithoms, shelly bottom. Dr. Stimpson. 



Psolus phantapus Oken. 



Psolu^ kevigatus Ayres, op. cit. p. 25. P . pliant apm ^t\m\i. Inv. 

 p. 16; These Proc. iv, p. 67; Bronn, PL 47, fig. 4, copied from 

 Cuvier. a poor figure. 



Chelsea Beach, Mass. ; Grand Menau, at low water and in forty 

 fathoms ; and at Eastport, Me., at low-water, buried among ])ebbK's, 

 Dr. Stimpson. I have dredged it at Mt. Desert, Me., in fifteen tath- 

 oms, rocky bottom. 



The following species has many structural peculiarities that sepa- 

 rate it from typical species of Paolus, and entitle it to rank as a dis- 

 tinct genus. 



LOPHOTHURIA 



f/en. nov. 



Cuvier ia (pars) Pcron, 1817, (not of Per. and Les. 1811). P;<oIhs 

 (pars) Liitken, Gronlands Echinod. 1857. 



Tentacles ten, arborescent, and greatly subdivided, about as long 

 as the body in expansion. Body covered above by large imbricated 

 plates, with a flat naked surface beneath, with a crowded row of am- 

 bulacral suckers on each side, but without a median row, which is im- 

 perfectly represented by a crowded gi'oup of suckers at each end of 

 the flat surface, mingling with tlioso of the lateral rows. Naked part 

 of the body, below the tentacles, retractile, and having ten vermicular 

 appendages near its junction with the plated portion, corresponding 

 with th^ ambulacra and tentacles. Tentacles connected at base by a 

 narrow web. 



P.iolus* differs from this genus in having a double median row of 

 suckers beneath ; in its less branched tentacles, without a basal web ; 

 and in having five double rows of slender, sucker-like, ambulacral ap- 

 pendages along the naked part of the body below the tentacles. The 

 anal region is also greatly prolonged. 



* Typical sppcimpn of P. phantapus from Denmark, iu alcohol, with tentacles 

 expanilcd, sent by Dr. Chr. Liitken. 



PROCEEDINGS B. 8. N. H.— VOL. X. 23 JULY, 1866. 



