Glossary of Technical Terms 



Inarticulate. Not jointed. 



Incisors. The front or cutting teeth. 



Inferior pharyngeals. Synonymous with pharyngeals, q. V. 



Infraoral. Below the mouth. 



Interhamal spines. Elements supporting the anal fin. 



Interhcemals. Bones to which anal rays are attached, in fishes. 



Interhyal. Upper hyoid bone attached to hyomandibular. 



Intermusculars. Synonym of epipleurals, q. v. 



Interneural spines. Elements supporting the dorsal fins. 



Interspinous bones. The interneurals and the interhaemals. 



Intermaxillaries. The premaxillaries ; the bones forming the middle of the front 



part of the upper jaw, in fishes. 



Interneurals. Bones to which dorsal rays are attached, in fishes. 

 Interopercle. Membrane bone between the preopercle and the^branchiostegals. 

 Inter orbital. Space between the eyes. 

 Interspinals. Bones to which fin rays are attached (in fishes) ; inserted between 



neural spines above and haemal spines below. 

 Isocercal (tail). Last vertebrae progressively smaller and ending in median 



line of caudal fin, as in the codfish. 

 Jugular. Pertaining to the lower throat; said of the ventral fins, when placed 



in advance of the attachment of the pectorals. 

 Keeled. Having a ridge along the middle line. 

 Lacustrine. Living in lakes. 



Lamellae. Plate-like processes like those inside the bill of a duck. 

 Larva. An immature form, which must undergo change of appearance before 



becoming adult. 



Lateral. To or toward the side. 

 Lateral line. A series of muciferous tubes forming a raised line along the sides 



of a fish. 



Lateral processes. Synonym of parapophyses, q. v. 

 Laterally. Sidewise. 



Lunate. Form of the new moon ; having a broad and rather shallow fork. 

 Mandible. Under jaw. 

 Maxilla, or maxillary. Upper jaw. 

 Maxillaries. Outermost or hindermost bones of the upper jaw, in fishes; they 



are joined to the premaxillaries in front, and usually extend farther back 



than the latter. 



Mesethmoid. Synonym of ethmoid, q. v. 

 Mesopterygoid. A bone of the suspensorium. 

 Metapterygoid. A bone of the suspensorium, or chain supporting the lower 



jaw. 



Molars. The grinding teeth; posterior teeth in the jaw. 

 Muciferous. Producing or containing mucus. 

 Myocomma. A muscular band. 

 Myodome. Cavity under the brain for the reception of the rectus muscles of the 



eye. 



Nape. Upper part of neck, next to the occiput. 

 Nares. Nostrils, anterior and posterior. 

 Nasal. Pertaining to the nostrils. 

 Nasal plate. Plate in which the nostrils are inserted. 

 Neural arch. An opening through the base of the neural spine for the passage 



of the spinal cord. 



Neural canal. The neural arches as a whole. 

 Neural processes. Two plates rising vertically, one on each side of the centrum 



of the vertebra, which unite toward their ends and form a spine. 

 Neural spine. The uppermost spine of a vertebra. 

 Nictitating membrane. The third or inner eyelid of birds, sharks, etc. 

 Notochord. A cellular chord which in the embryo precedes the vertebral column. 

 Nuchal. Pertaining to the nape or nucha. 



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