152 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY. 



[Bull. 



Rough-skinned Thyone, 136. 



Sand-dollar, 96, no. 



internal anatomy, 96. 

 Sea-urchins. See Echinoidea. 

 Single-striped Thyone, 135. 

 Slender-armed starfish, 58, 63. 



development, 58. 

 Spatangoidea, 106. 

 Spinulosa, 59. 

 Starfish, abnormalities, 44. 



age at sexual maturity, 42, 48. 



artificial fertilization, 50. 



breeding season, 49. 



damage to oysters and other 

 mollusks, 33, 57. 



effect of mutilation, 47. 



fertilization, 49. 



habits of young, 56. 



losses caused by, 34. 



method of feeding, 30. 



methods of controlling injuries 



by, 35, 37, 39, 56, 58. 



species of, 58. 



See also Asteroidea. 

 Strongylocentrotus drbbachiensis, 

 14, 85, 86, 89, 1 06, 108. 



description, 109. 



geographical distribution, 108. 



habits, 109. 

 Syria pta, 15, 124, 127. 



habits and food, 124, 138, 141. 



regeneration, 127. 



Synapta inherent, 15, 129, 138, 140, 

 142. 



description, 139. 



geographical distribution, 138. 



habits, 124, 138, 141. 

 Synapta roseola, 15, 129, 141. 



description, 141. 



geographical distribution, 142. 

 habits, 142. 



Thyone, 15, 116. 



alimentary canal, 116. 



body walls, 121. 



calcareous ring, 118. 



cloaca, 118. 



food, 123. 



habits, 122. 



internal anatomy, 116. 



musculature, 121. 



nervous system, 121. 



reproductive organs, 121. 



respiratory tree, 119. 



water- vascular system, 119. 

 Thyone briareus, 15, 114, 117, 120, 



129, 133- 



description, 133. 



geographical distribution, 133. 

 Thyone scabra, 15, 114, 122, 129, 

 136. 



description, 137. 



geographical distribution, 136. 

 Thyone unisemita, 15, 114, 122, 129, 



I35 : 



description, 135. 

 geographical distribution, 135. 

 Tube-feet, ophiuran, 71. 

 starfish, 22. 



Variation in number and arrange- 

 ment of rays, starfish, 43. 



Water-vascular system, holothurian, 



119. 



ophiuran, 73. 

 sea-urchin, 90. 

 starfish, 26. 



Zygophiurae, 79. 



