



forgetfulness. SerscheL 

 land. Burmeister. Lyell. 



NON'ETJMINANTIA, The order artio- 

 dactyla, or those animals possessing 

 an even number of toes, is divided 

 into two families, nonruminantia 

 and ruminantia ; the hippopotamus, 

 pig, &c., are examples. 



NO'RKA. The name given by Cron- 

 stadt to an aggregate of quartz, 

 mica, and garnet. This aggregate 

 is included by Kir wan in the gran- 

 atines. 



NO'RFOLK CRAG. An English tertiary 

 formation belonging to the older 

 pliocene. It is observed to rest on 

 the chalk and on the London clay. 

 It consists of irregular beds of fer- 

 ruginous sand clay, mixed with 

 marine shells. According to an 

 account of Mr. S. Woodward, if a 

 line be drawn from Cromer, on the 

 northern coast of Norfolk, to Way- 

 burn, about six miles west, and 

 from thence extending in a southerly 

 direction towards Norwich, about 

 18 miles, it will comprise all the 

 regular beds of Norfolk crag. 



NO'RITE. The name assigned by 

 Esmarck to a rock not yet deter- 

 mined; some of its characters 

 appear to belong to diorite, and 

 some to gabbro. 



NOTHO'CERAS. M. Barrande has lately 

 established a new genus of Cepha- 

 lopod under this designation. It 

 is intermediate between Nautilus 

 and Goniatite, and is of the Upper 

 Silurian age. 



NOTHO'SAURTJS. A reptile of lacertian 

 or lizard-like character, of the new 

 red sandstone era. 



NOVA'CULITE. (from novacula, a razor, 

 Lat.) The Wetz schiefer of Wer- 

 ner; argile schisteuse novaculaire 

 of Hauy. Honestone. See Hone. 



NI/CLEOLI CES. A genus of radiaria, 

 twelve species of which have been 

 determined as occurring in the 

 chalk formation, and six species as 

 occurring in the oolite. 



NU'CULA. A genus of marine bivalve 



[ 318] 



IS" U M 



shells belonging to the family 

 Arcacea. An inequilateral, equi- 

 valved, transverse, subtrigonal bi- 

 valve ; covered with an epidermis. 

 The hinge linear, bent at an angle 

 formed by numerous, alternately 

 inserted teeth ; muscular impres- 

 sions, two, simple; beaks approxi- 

 mating, and turned backwards. 

 The recent species of this genus 

 are found in estuaries, and in the 

 ocean, at depths varying to sixty 

 fathoms, in mud and sand. Several 

 fossil species are described. 



NU'DIBRANCHIATA. The second order 

 of the class Gasteropoda. The nu- 

 dibranchiata have no shell what- 

 ever; neither are they furnished 

 with any pulmonary cavity, their 

 branchiaa being exposed on some 

 part of their back, from which cir- 

 cumstance they have obtained their 

 name. The triton, doris, &c., are 

 examples. 



NT^MMULITE. (from nummuSf money, 

 Lat. and \i0os, a stone, Gr.) 

 The nummulites compose a fossil 

 extinct genus of multilocular ce- 

 phalopods, presenting, externally, 

 a lenticular figure, without any 

 apparent opening, and, internally, 

 a spiral cavity, divided by septa 

 into numerous chambers ; they do 

 not possess a siphuncle, but their 

 chambers communicate by means 

 of small foramina with each other. 

 They have obtained their name 

 from their supposed resemblance to 

 pieces of money. It is of stone 

 composed of Nummulites that the 

 pyramids of Egypt are constructed. 

 Nummulites have been named He- 

 licites, from their spiral structure ; 

 Phacites, from their resemblance 

 to a lentil ; and Salicites, from the 

 supposed resemblance of their sec- 

 tions to the leaf of the willow. 

 Pliny is supposed to refer to them 

 under the name of Daphnias when 

 he mentions that Zoroaster em- 

 ployed these substances for the cure 

 of epilepsy. They have been also 



