1101 



TRILOBITES. 



TRIMERA. 



1103 



II. Trilobites having the power of rolling themselves into a ball. 



Section 1. Trilobites having the power of rolling themselves up into 

 a ball with the axis of the body constructed posteriorly, the shell 

 granulated, and generally more than ten body-rings. 



A. Trilobites capable of rolling themselves up, and whose facial 

 suture terminates exactly in the angles of the cephalic shield. 



11. Calymene. 



12. Jlomahnottu. 



Calymene Sotoninyii, partially rolled up. 



B. Trilobites having the power of rolling themselves up, whose 

 facial auture terminates in the external lateral margin of the cephalic 

 shield. 



13. PKaeopt. 



C. Trilobites capable of rolling themselves up, having the axis of 

 Hie body diminishing posteriorly, and their facial suture extending to 

 the posterior margin of the cephalic shield. 



14. Cyphatpii. 



15. Proetiu. 



16. Archfjjunui. 



Section 2. Trilobites possessing the capacity of rolling themselves 

 up ; the body axis not shortened posteriorly ; the shell finely 

 lineated ; the caudal shield not having radiated lateral furrows. 



A. The body-axis consisting of ten equal rings. 



17. lUaniu. 



B. The body-axis consisting of nine rings. 



18. Dyiplaniu. 



C. The axis of the body consisting of eight equal rings. 



19. Ataphut, 



Ataphut (A'iteo) Armadillo, 

 a, ccn from above ; i, profile, the animal rolled up. 



D. Six-jointed Trilobites capable of rolling themselves up, aud 

 having the axis of the body equally broad throughout. 



20. Ampyx. 



In an appendix, Burmeister describes Agnottus, which is an anomalous 

 form. The species are small, with nearly circular bucklers of two kinds, 

 which M. Brongniart considers to have covered the whole of the body 

 to which each of these discs belonged, and which Uulman regards as 

 being only portions of the body, nnd as having belonged, some to the 

 head, others to the abdomen, of a Trilobite whose thorax must have 

 been reduced to a rudimentary state, or at least must have remained 

 membranous. These two sorts of bucklers or shields have nearly the 

 same form and size, but differ in the disposition of the eminences 

 perceptible on their surface, aud are divided into three lobes. The only 

 species known is the Agnotltu of Brongniart, Battus of Dalman. 



Agnottiu iiiti/ormu. (After Dalman.) 



The following is a list of the British genera of Trilobites, with their 

 number of species: Acidapiit, 1 species; Amphion, 4; Ampyx, 4; 

 Agnoittu, 2; Argci, 1; Aiaphui, 20; JUronteus, 2; Mummies, 1; Caly- 

 mene, 11; Cerauriu, 1; Eurypterut, 1; Griffithid.es, 4; llarpes, 3; 

 Jfomalonotus, 4 j llixniu, 4 ; Itoteles, 10 ; Nuttainia, 2 ; Ogyyia, 2 ; 

 Olenue, 1 j Paradotcidtt, 3 ; I'/utcopt, ; I'hillipiia, 7 ; Itcmoiileuridei, 



R 7',- 1 .1 ii, /, i/ * 1 (I 



6 ; Trinucltui, 10. 



In Mr. McCoy's ' Synopsis of the Carboniferous Fossils of Ireland," 

 the following new species are described aud figured : Griffil/tides cat- 

 caratus; Phillipsia cailata ; P. Oolii ; P. discors; P. mucronata; P. 

 quadrissrialis. 



In Mr. McCoy's ' Synopsis of the Silurian Fossils of Ireland,' col- 

 lected by Mr. Griffith, the following new genera are described and 

 figured : Forbesia ; Portlockia ; Tiresias ; Trinodus. 



TRI'MERA, the fourth section of the order Coleoptcra among 

 Insects, according to the arrangement of Latreille. The insects popu- 

 larly known as Lady-Birds and Pufi'-Ball-Beetles are characteristic of 

 the families composing it. 



The insects of this division have four palpi, two of which are labial 

 and two maxillary. These palpi are short and slender, or with an 

 enlarged terminal joint. The antenna: are also short and thickened at 

 their extremities, in some species gradually, in others suddenly. The 

 body is oval or hemispheric ; the head is not produced anteriorly, and 

 is deeply inserted in the thorax, which is short and transverse, or 

 somewhat square and flattened. The abdomen, generally flat beneath 

 and ample, is covered by the elytra, which are arched, very convex, 

 and never truncated at the tip. The legs are short, with tarsi appa- 

 rently composed of three joints, but in reality of four, the second 

 being bilobed, aud concealing between its lobes a minute third joint, 

 the seeming absence of which has given origin to the name of the 

 section. Westwood, with more propriety, has styled the division 

 Pse udo- Trimera. 



Latreille divided the Trimera, into three families, which he styles 

 Fungicolie, Aphidip/iagce, and Pselaphii. The last has however been 

 united by English entomologists with the Staphi/linida;, to which 

 insects their truncated elytra, too short to cover the abdomen, and 

 general aspect, give them a great resemblance. Westwood includes 

 among his Pteudo-Trimcra, the Clavipalpi, the seventh aud last family 

 of Tetramera in Latreille's arrangement. He styles the family En- 

 tylidce, from the typical genus Erotyliis. They are chiefly exotic 

 insects, supposed to feed on vegetable matter ; and were regarded by 

 Latreille as connecting the Cydica (Cassida, Chrysomela) with his 

 trimerous family Fungicoke. 



The Fnngicolcs of Latreille (Endomychidte of British authors) are so 

 styled from their habitat in the interior of cryptogamic plants of the 

 class Fungi, on which they feed. Some species are found under the 

 damp bark of trees, where however their food consists of the Funyi 

 which are peculiar to such a locality. The perfect insect is very 

 convex, oval, and glabrous, and many of the species are ornamented 

 with brilliant colours. The antennae are composed of eleven joints 

 thickened towards the extremity, and larger than the head and thorax. 

 Their elytra cover the abdomen, and the penultimate joint of the tarsus 

 is deeply bilobed. The only known larva of an insect of this family is 

 that of Endomychui coccincus, said by Samouelle to resemble the 

 common glowworm. Curtis figures it. Westwood remarks that it 

 has more analogy to the larva of the Silphidce than to that of the 

 glowworm or of Coccinetla. The British species of this family belong 

 to the genera Endomychus and Lycoperdina. They are but few in 

 number. One of them, the Lycoperdina Bovistce is found in great 

 numbers inhabiting that common puff-ball the Lycoperdon Bovisla. 

 Etimorphus is an American genus, described by Weber, distinguished 

 by the dilated flattened three-jointed clubs of the antenna!. It includes 

 several eccentric forms, in which the elytra have broad dilated margins 

 with the anterior tibia) notched. Mr. Curtis considers them as related 

 to those singular insects which constitute the genus Mormolyce, but 

 Westwood regards the relation as one of the most remote analogy. 



The Apliidiphagce (Coecinellida; of English authors) are animal- 

 feeders preying upon Want-Lice (Aphides), and correspond to the 

 I.inmuau genus Coccinclla. In shape they are very convex and hemi- 

 spheric, and have antennae shorter than those of the last family, termi- 

 nated by a compressed club in the form of a reversed triangle. The 

 larva is depressed, ovate, and fleshy. The three anterior segments of 

 its body are largest, and the abdominal ones tubercled aud spotted. 

 Its head is small, with very minute antenna; and thick maxillary palpi. 

 The pupa is found attached by its posterior extremity to a leaf, aud 

 undergoes its metamorphosis in that position. The larva emits from 

 its tubercles a yellowish fluid having a disagreeable scent. When the 

 perfect insect is laid hold of, it gives out a similar secretion from its 

 joints, and folds its legs up as if simulating death. 



The insects of this family are remarkable for brilliant colouring, 

 being generally red or yellow, with black, red, white, or yellow spots. 

 Individuals of the several species are so extremely variable and dif- 

 ferent from each other in their markings, as to render the construction 

 of specific diagnoses in tills family more difficult than in any other 

 tribe of Coleoptcra. Some have supposed that many of these varieties 

 are hybrids between the sexes of different species, but M. Audouin 

 maintains that the eggs produced from the uniou of allied species in 

 the genus Coccinella, are sterile. They creep slowly, but Hy well, aud 

 many kinds are gregarious. The eggs are deposited in yellow patches 

 among the plant-lice, so that the larva is hatched in the midst of its 

 food. They abound in our fields and gardens, and are among the first 

 beetles which come out in spring. They appear sometimes in immense 

 swarms, and spreading over the fields cause needless alarm to the 

 farmer, to whom, far from being a pest, they are a blessing, from the 

 fierce war they wage against his enemies the Aphidet. 



