368 GLOSSARY OF TECHNICAL TERMS. 
Larva. An immature form, which must undergo change of appear- 
, ance before becoming adult. 
Lateral. To or towards the side. 
Lateral line. A series of muciferous tubes forming a raised line along 
the sides of a fish. 
Laterally. Sidewise. 
Lobate. Furnished with membranous flaps, — said of the toes of birds. 
Longitudinal. Running lengthwise. 
Loral plate. Plate between eye and nostril of a serpent, before and 
below preocular when this is present; its longest diameter hori- 
zontal. 
Lores. Space between eye and bill. 
Lunate. Form of the new moon; having a broad and rather shallow 
fork. 
Mammary glands. Glands secreting milk. 
Mandible. Under jaw (or in birds, either jaw). 
Mazilla. Upper jaw. 
Mazillaries. Outermost or hindmost bones of the upper jaw, in fishes; 
they are joined to the premaxillaries in front, and usually extend 
farther back than the latter. 
Metacarpus. The hand proper, exclusive of the fingers. 
Metamorphosis. A decided change in form. 
Metatarsus. The foot proper. 
Molars. The grinding teeth; posterior teeth in the jaw. 
Monogamous. Pairing ; said of birds. 
Muciferous. Producing or containing mucus. 
Myocomma. A muscular band. 
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 spine. The uppermost spine of a vertebra. 
Nictitating membrane. The third or inner eye-lid, of birds, sharks, 
ete. 
Notochord. A cellular cord, which in the embryo precedes the verte: 
bral column. 
Nuchal. Pertaining to the nape or nucha. 
Obscure. Scarcely visible. 
Obsolete. Yaintly marked; scarcely evident. 
Obtuse. Blunt. 
Occipital. Pertaining to the occiput. 
Occipital plates. Plates on the head of a serpent, behind the vertical 
plate. 
Occiput. Back of the head. 
Ocellate. With eye-like spots, generally roundish and with a lighter 
border. 
Oid (suffix). Like, —as Percoid, perch-like. 
Opercle, or operculum. Gill cover ; the posterior membrane bone of the 
side of the head, in fishes. 
