No. 414] MORTH-AMERICAN INVERTEBRATES. 489 
adopted and the diagnostic characters of this interesting little 
holothurian. The remaining two species are very curious and 
noteworthy ones from the coast of California, collected during 
the summer of 1900 by Mr. Benjamin Thomas. They are 
Thyone rubra Clark and Thyonepsolus nutrians Clark. Descrip- 
tions of these two species are now in press. Each of these 
five species bears at present only a nomen nudum, but it has 
seemed best to include them, nevertheless, in order to make 
the key as complete as possible. 
KEY TO THE SPECIES UNDER EACH GENUS. 
Synapta. 
( Viviparous; mm. long; reddish-brown or 
greenish, odi ud white; lives in seaweed 
S. vivipara (Oerst.) 
Radial pieces of cal- Biscayne Bay, Florida ; Bermuda, Jamaica; Brazil. 
careous ring perfo- 
SP N B pd larger, 250 mm.; white, yel- 
rated for passage 4 
of the nerve ish, or kn — lives buried in sand 
(Fie. s) . . S. inherens (O. F. Müll) 
Widely distributed in Northern Hemisphere; Maine to South 
Carolina in Western Atlantic; Puget Sound, southward on 
Pacific coast. Also Mediterranean, Eastern Atlantic, North Sea, 
L and Arctic Ocean. 
Radial pieces of calcareous ring, not iea but me notched 
(Fig. 9; 1 100 mm.; rosy red. . . . à . roseola (Verr.) 
© lovee focis or buried in the sand. Southern side of Cape Cod, Buzzards 
Bay, Tete d idea Sound, and Bermuda. 
Chiridota. 
Wheel Papille very numerous, scattered over all the interambulac 
besides wheels there are many small slightly curved rods UC sola (Pourt.) 
Viviparous; roo mm. long; deep flesh color, wheel papille white; under stones and 
loose rocks, and in sand; Key West, Biscayne Bay, Bermuda, Jamaica, and Brazi 
Wheel papillæ in rows of 20-30 in each dorsal interambulacrum an 
3-12 in each ventral one; North Atlantic coast . . . C. but (Fabr.) 
Wheel papilla in only three interambulacra; Alaskan species C. discolor Esch. 
two saar are practically PEAP and further study will probably 
the i to be ide ccur under rocks, o comparatively shallow 
Wa: 
ter; may reach a soap m size; color very bner from gray to pink. 
