386 INDEX-GLOSSARY. 



Muscle-corpuscle, 91. 



Muscle-fibre, 91, 192, 201, 209. 



Muscularis mucosse, in Vertebrates A thin layer of unstriated muscle 



traversing the mucous membrane of the stomach and intestines, 192, 



288. 

 Muscular system Distoma, 34; Tsenia, 43; Ascaris, 48; Lumbricus, 58, 



64; Hirudo, 81; Astacus, 91; Anodonta, Unio, 119; Helix, 122; 



Amphioxus, 144; Scyllium, 168; Rana, 208; Columba, 252; Lepus, 



299. 



Musculature The muscle system, 34. 

 Mussel (salt-water), 122. 

 Mussel (fresh- water), 100-122. 

 Mustelus, 167. 

 Myocoele (/xus, a muscle ; /coTXos, hollow) The cavities of the mesodermic 



somites, 149. 

 Myoccelomic, 149. 



Myophan striations (M^S; 0a/o/x<, 0ai/- } appear), 13, 16. 

 Myomere = Segment, muscle, q.v. 

 Myotome = Segment, muscle, q.v. 

 Mysis, 109. 



N 



Nail, 176. 

 Nares (nares, the nostrils) External (anterior), 175, 218, 229, 268, 275 ; 



Internal (posterior), 189, 218, 241, 285. 

 Nates, 302. 

 Nearctic, 350, 353. 

 Nebalia, 86. 

 Nemathelmia (v*ina, a thread ; e\/>uvs, intestinal worm) Thread worms, 



340 ; Chap, iv., 47. 



Nematocyst (Thread-cell), 22, 24, 25, 312. 

 Neotropical, 350, 352. 



Nephridiopore The external opening of a nephridium, 61. 

 Nephridium (dim. of i/e^/oos, a kidney) An excretory tube by which waste 



products are carried from the coelom, or a section of it, to the exterior, 



60, 70, 80, 118, 129, 316. 

 Nephrops, 109. 



Nephrostome (e0pos; O-TO/XO, a mouth) The internal opening of a nephri- 

 dium, 61. 

 Nerve Nerve-exits, 233, 274; Cranio-spinal nerves, 319; Scyllium, 169; 



Eana, 211; Columba, 253; Lepus, 302; Abducent (vi.), 170, 212; 



Auditory (viii.), 133, 171, 213; Brachial, 213; Branchial, 171; Buccal, 



