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NATURE 



{April i, 1880 



that this is the mode of division above the secondary 

 axillaries. 



Despite Liitken's arguments to the contrary, Muller's 

 division of the true Crinoids into Tesselata, Articulata, 

 and Costata is adopted with but a few slight modifica- 

 tions, on the ground that it furnishes ■well-defined natural 

 groups. 



The grouping of the families in each sub-order is in 

 great part a new one, though based to some extent on the 

 works of Roemer, Angelin, and Wachsmuth. The sub- 

 order Tesselata includes twenty-six families which arc 

 arranged in five sections, chiefly according to the struc- 

 ture of the vault, and the relations of the oral plates. 

 Seven of these families are new, while some of those 

 which date from an earlier period have been slightly 

 modified in their extent. The Articulata fall into seven 

 families, of which two are new, viz., the Eugeniacrinida 

 and Pli'catocrinidce, while the limits of Roemer' s family, 

 Holopodida, are slightly altered. The recent Hyocrinus, 

 which is referred by Sir Wyville Thomson to the 

 Apiocrinidce, is regarded by Prof. Zittel as most probably 

 identical with Plicatocrinus, and the well-known genus 

 Rhizocrinus of M. Sars is identified with the very im- 

 perfectly described Conocrinus of d'Orbigny, the latter 

 name being resuscitated on grounds of priority, while 

 ■nus is reduced to the rank of a synonym. We 

 venture to think that this is somewhat inexpedient, for 

 Sarb's name is now universally employed, and there can be 

 no possible doubt as to the characters of the type to 

 which he gave it ; whereas Zittel himself admits that 

 d'Orbigny's diagnosis of Conocrinus is incomplete and 

 even partially incorrect. 



Among the Cotnalulida the fossil Solanocrinus with 

 external basals, is retained as a type distinct from that of the 

 recent and fossil Antedons which lack this peculiarity, 

 although Schluter, like others before him, has recently 

 attempted to merge Solanocrinus in Antedon. There is one 

 portion of the diagnosis of this type in which clearness has 

 been too much sacrificed to brevity. It is as follows. "Dorsal 

 organ (heart) round, without radial pits." The meaning 

 which these words are intended to convey is that the 

 centrodorsal piece has a round central cavity in which the 

 chambered organ (the so-called heart) was lodged, and 

 that there are no radial pits around its opening. In 

 recent Comalula, however, the presence or absence of 

 these pits is far too irregular within specific limits to be 

 of any systematic value, while Quenstedt has found them 

 to be sometimes present in Solanocrinus, although, 

 according to Zittel, they should be absent. 



The Cystids and Blastoids are classified according to 

 the systems proposed by Miiller and Roemer respectively. 

 Agclacrinus is referred to the Cystids, and not made the 

 type of a new class as is sometimes done in this country ; 

 while Codonastcr is transferred from the Blastoids to the 

 Cystids, in accordance with the views of the late Mr. 

 Billings. Stephanocrinus, on the other hand, placed by 

 Roemer among the Cystids, is here regarded as a 

 Blastoid. 



The Starfishes are all grouped together into one class, 

 the Asteroidea, which contains the two orders Ophiuridce 

 and Stelleridce. The palaeozoic forms of the latter, with 

 alternating ambulacral plates, are in accordance with 

 Bronn's classification, separated as Encrinasteria from 



the true Stellerids or Asleria vera. These are classified 

 chiefly according to the system of Miiller and Troschel, 

 which has been the basis of almost all palaeontological 

 work on the group, though the author adnuts that it 

 requires much revision as regards the recent forms. 



The classification of the Echinoidea, however, contains 

 some new features. The name Echinocyslitcs, proposed 

 by Wyville Thomson in 1864 for a remarkable palaeozoic 

 form which he regarded as intermediate between Cystids 

 and Echinids, is discarded in favour of Cystocidaris, 

 Zittel, on the ground that Hall used the same name three 

 years later for a true Cystid from the Upper Silurian of 

 Wisconsin. Cystocidaris is made the type of a new order 

 which, together with the Bothriocidarida and the Pcri- 

 schoechinida, constitute the sub-class Palechinoidea, Zittel. 

 LoveVs arrangement of the Perischoechinida is the one 

 adopted, except that the family name Palacchinida, 

 M'Coy, gives way to Melonitidce, Zittel. The other 

 Urchins constitute the sub-class Euechinoidea, Bronn, the 

 regular forms being grouped into four families, viz., the 

 Cidarida, Salcnida, Ecliinothurida:, and Glyphostomata, 

 this last including the sub-families Diadematida and 

 Echinida. In view of the observations of Lovdn and 

 Ludvvig on the mobility of the plates of the hinder inter- 

 ambulacrum in the Spalangida and Holastcrida, the 

 author does not regard the Echinolhuridce as so clearly 

 related to the Perischoechinidce as has been supposed by 

 some writers, but considers the characters of their am- 

 bulacral and interambulacral areas to indicate the 

 Diademalida? as their nearest allies. 



The primary classification adopted for the irregular 

 Urchins is that of de Loriol, which depends upon the 

 presence or absence of a dentary apparatus. Each of 

 his sub-orders, Cnathostomata and Atelostomata is made 

 to include three families, those of the first being the 

 Echinoconida, d'Orb., the Conoclypeida', Zitt., and the 

 Clypeastrida; Ag., while in the Atelostomata are included 

 the Cassidulida, Ag., Holasterida; de Loriol, and the 

 Spalangida; Ag., as arranged by de Loriol. 



The illustrative woodcuts, like those in the earlier Partsof 

 the " Handbook,"are remarkably clearand effective, though 

 in a few cases they might, with advantage, have been a 

 trifle larger. Many of them are new and original, while 

 others, especially in the Crinoid section, are copied from 

 the works of the American palaeontologists and from 

 Angelin' s " Iconographia." The figures of Echini in the 

 latter half are mostly of exceeding merit, while many 

 beautiful analytical diagrams are reproduced from Loven's 

 " Echinoid Studies." 



This Part of the " Handbook," which seems to us fully 

 to keep up the high character of its predecessors, con- 

 cludes with p. 564 of the first volume. The chapters on 

 the Vermes, Mollusca, Arthropoda,an& Vertebrata have yet 

 to appear, and will do so, we trust, at no very distant date. 



m 



MEDICINE PAST AND PRESENT 

 Pharmacology and Therapeutics; or, Medicine Past and 

 Present. By Dr. Lauder Brunton, M.D.,&c. (London: 

 Macmillan and Co., 1880.) 



DURING the last two or three decades, and especially 

 during the last decade, a change has been going 

 on in therapeutics, that is, in the doctrines of remedies 



