THE POPULAR EDUCATOR. 



in these beds ; these curious creatures are restored in our 

 sketch of a forest of the period. 



The Purbeck beds are more or less fresh-water formations. 

 The upper division, some fifty feet in thickness, is purely fresh- 

 water, as declared by the fossils Paludina, Limn&a, Planorbis, 

 Cyclas, Unio. 



The middle Purbeck is partly fresh-water and partly marine, 

 but is noted for a certain thin bed of marl, only a few inches 

 thick, near its base, in which have been discovered the remains 

 of many species of mammalia. From an area of not 500 square 

 yards have been taken the skeletons of some fourteen species. 

 The Plagiaulax is one of the most prominent, an insectivorous 

 mammal. This discovery was a decided hint that it is danger- 

 ous to draw any general conclusion concerning the land life of 

 the globe, for here we have, in a small space, far more evidence 

 of mammalian life than all the previous strata put together have 

 furnished. 



FOSSILS WHICH CHARACTERISE THE LOWER OOLITE. 

 Plants. Bucklandia squamosa ; Halymenites ramulosus ; Splienopteris 



cysteoidcs. 



Protozoa. Spongia cymosa, etc. 

 Corals. Isastrsea Conybeari; Millepora pyriformis. 

 Bracliioyoda. Rhynconella coiicinna ; Terebratula globata, fimbria, 



cardiuia ; Discina grauulata. 

 Conchifera. Lima gibbosa, rigidula, impressa ; Trigonia angulata, 



duplicata ; Gervillia laevigata ; Avicula costata ; Gryphsea minuta, 



gigantea; luoceramus; Ostrsea rugulosa ; Pecten re tiferus, vagans ; 



Astarte orbicularis ; Corbula depressa ; Cypricardia ; Modiola 



compressa ; Trigonia cuspidata ; Nucula variabilis. 

 Gasteropoda. Pleurotomaria fasciata ; Nerita costata ; Alaria armata; 



Eulima commimis ; Fusus corouatus ; Natica ; Trochus ornatis- 



simus. 

 Cephalopoda. Ammonites corrugatus, Sowerbyi, subcontracts, etc. ; 



Belemnites abbreviatus, giganteus, f usiformis ; Nautilus dispansus. 

 Ecliinodcriimta. Echinus germiuaus; Clypeus Agassizii; Pentacrinus 



Milleri. 



Annelida. Serpula grandia, etc. 

 Insecta. Coccinella Wittsii. 

 Fish. Hybodus crassus j Strophodus magnus ; Acrodus leiodus ; 



Lepidotus tuberculatus ; Asteracanthus acutus. 

 Reptiles. Cetiosaurus longus; Megalosaurus Bucklandi; Ptcrodactylus 



Bucklaudi. 

 Mammalia. Amphitherium Prevostii . Phascolotherium Bucklandi ; 



Stereognathus ooliticus. 



FOSSILS WHICH CHARACTERISE THE MIDDLE OOLITE. 

 Plants. Carpolithes couicus. 

 Sponges. Manon foliaceum ; Spongia floriceps. 

 Corals. Calamophyllia Sokesii ; Isastreea explanata ; Thamnastnea 



rotata. 

 Brachiopoda. Discina latissima; Lingula ovalis ; Rhynconella lacunosa ; 



Terebratula insignia. 

 Conchifera. Avicula expansa, ovalis ; Gryphcea bilobata, mima; Ostreea 



inseqv.alis, deltoidea ; Prima granulata ; Corbis ovalis ; Nucula 



elliptica ; Pecten articulatus ; Astarte extensa ; Pholas compressa. 

 Gasteropoda. Alaria composita; Pleurotomaria depressa ; Bulla elon- 



gata ; Natica nodulata ; Turbo f uniculatus ; Turritella rnuricata. 

 Cephalopoda. Ammonites annularis, bifrons, Duucani, Jason, cordatus, 



etc. ; Belemnites anomalus, gracilis, abbreviatus; Nautilus hexa- 



gouus. 

 Echinoderma'-a. Auiphiura Prattii ; Astropecten rectus ; Echinus 



gyratus, cidaris, corouata, spinosa. 

 Annelida. Serpula vertebralis. 

 Crustacea. Glyphsea scabrosa. 

 Fish. Lepidotus inacrocbeirus ; Strophodus ; Hybodus obtusus. , 



CHARACTERISTIC FOSSILS OF THE UPPER OOLITE. 



Plants. Chara Purbeckensis ; Cyadeoidea microphylla ; Zamiostrobus 



Fittoni. 



Corals. IsastrsBa oblonga. 



Brachiopoda. Rhynconella inconstans, varians ; Terebratula impressa. 

 Conchifera. Ostrasa Iceviuscula ; Pecten distriatus ; Astarte lineata, 



cuiieata; Mytilus pectinatus; Modiola pallida; Trigouia incurva; 



Cucullsea oblonga. 

 Gasteropoda. Patella latissima ; Pleurotomaria reticulata, rugata ; 



Natica elegans ; Limnea ; Paludina ; Planorbis ; Ostrca. 

 Cephalapoda. Ammonites anceps, triphiatus, macrocepbabus. 

 Echinodermata. Cidaris spinosa; Echinus perlatus; Pygurus penta- 



gonalis. 



Crustacea Glyphoea rostrata. 

 Fish. Asteracanthus oruatissimus ; Hybodus acutus ; Strophodus 



reticularis ; Lepidotus minor. 

 Reptiles. Ichthyosaurus trigonus ; Plesiosaurus affinis ; Chelone 



planiceps ; Nothetes destructor. 

 Mammalia. Spalacotheriuin Brodiei ; Plagiaulax; Tricodon. 



LESSONS IN" SPANISH. XIY. 



IRREGULAR VERBS. 



THE irregular verbs in Spanish are such as do not conform 

 exactly in their manner of conjugation to the model verbs 

 (amar, comer, vivir). The deviations of each irregular verb 

 are in most cases but slight, yet important to be known, as 

 : most of the irregular verbs are in general use. 



There are thirty-nine of the different irregular verbs : seven 

 ; of the first conjugation, seventeen of the second, and fifteen 

 I of the third. Many of these differ but very slightly from each 

 ' other. All the irregular verbs are conjugated like some one 

 I of these thirty-nine forms. Four of these viz., haber, ser, 

 \ estar, and tener have already been conjugated. 



Those verbs which undergo slight changes in the verb-roots 

 or verb-endings of certain tenses or persons of tenses, are not 

 on that account deemed irregular, since these changes tako 

 place solely to preserve regularity and uniformity of sound, 

 which would be dissimilar in some cases if these changes did 

 not take place. Both regular and irregular verbs undergo 

 such changes when required by the rules of pronunciation. 



Remark. In the following conjugations of the irregular 

 verbs, those persons of the moods and tenses only which deviate 

 from the regular conjugation are given. Thus, in the firs;; 

 verb, andar, no tense of the indicative mood except tb.3 per- 

 fect definite is given, because this verb is conjugated regularly 

 in the other tenses of this mood. The student is therefore to 

 remember that all moods, tenses, and persons not included in 

 the conjugation are regular. We have, however; in oJ] cases 

 given the participle and gerund, whether formed regularly or 

 not. 



IRREGULAR VERBS OF THE FIRST CONJUGATION. 



1. The irregular verb andar, to walk, is thus conjugated : 



INF. Past Participle. Audado, Gerund. Audaudo. 



IND. Perfect Definite. Anduve, anduviste, anduvo; auduvimos, andu- 

 visteis ; anduvierou. 



SUB. Imperfect. Anduviera or anduviese, ancluvieras or anduvieses, 

 amluvicra or auduviese; anduvieremos or anduvie'semos, anduvierais 

 or anduvioseis, audnvieran or anduviesen. First Future. Auduviere, 

 anduvieres, auduviore ; anduvio'remos, anduviereis, auduvioren. 



2. The irregular verb contar, to relate, is thus conjugated : 

 INF. Post Participle. Contado. Gerund. Coutaudo. 



IND. Present. Cuento, cneutas, cuenta ; , , cuentan. 



IMP. Cuente, cueiita, cuente ; , , cueuten. 



SUB. Present. Cueute, cuentes, cuente ; , , cuenten. 



This verb changes o of the verb-root into ue, in the three per- 

 sons singular and third person plural of the present indicative, 

 imperative, and present subjunctive. 



3. The irregular verb dar, to give, is thus conjugated : 

 INF. Past Participle. Dado. Gerund. Dando. 



IND. Present. Doy (no other Perso?is irregular). Perfect Definite. Df, 

 diste, dio ; dimos, disteis, dieron. 



SUB. Imperfect. Diera or diese, dieras or dieses, diera or diese ; 

 didramos or didseinos, dierais or dieseis, dieran or diesen. First 

 Future. Diere, dieres, diere ; die'remos, dioreis, dieren. 



4. The irregular verb jugar, to play, is thus conjugated : 

 INF. Past Participle. Jugado. Gerund. Jugando. 



IND. Present. Juego, juegas, juega ; , , juegan. 



IMP. Juegue, juega, juegue ; , , jueguen. 



SUB. Present. Juegue, juegues, juegue ; , , jueguen. 



This verb takes e before g of the verb-root in the three per- 

 sons singular and third person plural of the present indicative, 

 the imperative, and present subjunctive. 



5. The irregular verb tentar, to try, to tempt, is thus con- 

 jugated : 



INF. Post Participle. Tenfcado. Gerund. Tentando. 



IND. Present. Tiento, tientas, tienta ; , , tientan. 



IMP. Tiente, tienta, tiente; , , tienteu. 



SUB. Present. Tiente, tientes, tiente ; , , tienten. 



This verb takes i before e of the verb-root in the same per- 

 sons and tenses as are irregular in the preceding verb. 



6. The irregular verb errar, to err, is thus conjugated : 

 INF. Past Participle. Errado. Gerund. Errando. 



IND. Present. Terro, yerras, yerra ; , , yerrau. 



IMP. Yerre, yerra, yerre ; , , yerrcn. 



SUB. Present. Yerre, yerres, yerre ; , , yerren. 



This verb is irregular in the same persons and tenses as 



