ACANT1IMN. 



cylindrical, truncated, nd equally atte- 

 which an largely ojnaied and without 



Miokim Medilaraneum (Otto). 



-K i/wo describee the organism ou which he has established this 

 genus ai swimming by ejecting and absorbing the water by means of 

 the alternate dilatation and contraction of its two orifices. M. 

 Delle Chiaje ('Mem.,' torn, iil) seems inclined to believe that the 

 /Ww/na* of Otto is merely a fragment of a species of UolotAnna, 

 which he names JloloHatria t'A<rmw. Do Blaiiiville observes that it 

 Otto's description of the motion, tc., above stated, be correct, it is 

 probable that the animal is a true Siplion. 



"Among the genera," says De Blaiuville, " incerttt teda, which. 

 wrong or right, hare been connected with Phyuophora or Diphyet, 

 without even being very certain that they are animals, we shall cite 

 the following genera intentionally omitted in our work." 



Cvpultta (Quoy and Oaimard), placed among the Phyttophone, 

 whose capsules are disposed on each side of a very long axis, 

 established on an organised body, figured pL 87, fig. 4 16 in the 

 zoological part of the ' Voyage of the Uranie.' Not having met 

 with this animal in their second royage, MM. Quoy and Gaimard 

 doubt (' Astrolabe, Zoolog., 1 t. iv. p. 53 n.) whether it is an incom- 

 plete Pkyuopkora or a SUphomonite (Slephanomia I) with hollow 

 natatory organs. Cuvier places the genus between Hippoput and 



&ftmt 



Palytoma (Quoy and Qaimard, ' Zool. of the Uranie,' pi. 87, fig. 12, 

 18), which may be defined to be an oval mass of globular trivulvulur 

 corpuscles (corpuucules globuleux comme trivalves), and which 

 MM. Quoy and Qaimard conceive to be rather a liiphore than a 



Tetrayona (p. 10), (Quoy and Oaimard, ' Zool. of the Uranie,' pi. 86, 

 fig. 11). This the authors themselves ('Astrolabe,' iv. p. 108) have 

 recognised as being nothing more than the posterior point o 



and Grtgurimadu conduct us toward* tbu lowest j.ltwU. Thuw rela- 

 tions may be thus represented : 



MOLLUSCJL 



' ' 



Jtacemit (Delle Chiaje, Cuvier), figured by Delle Chiaje, ' Mem.' tab. 

 60, t 11, 12, and described as a globose vesicle endowed with a very 

 quick motion, and disposed towards an ovate shape ; but, observes 

 De Blainville, the figures and description are too incomplete to afford 

 a supposition of what it is ; in fact, Delle Chiaje confines himself to 

 stating that his Ractmit mala executes all the rotatory and rapid 

 motions at the surface of the water, and that those of each vesicle 

 are so lively that it has been absolutely impossible to pen.h, 

 the aperture with which, according to Delle Chiaje, they are pro- 

 vided. Cuvier only adds to the description of Delle Chiaje, who 

 also places Racemi* near the Phyuophora, a small membrane with 

 which each vesicle is furnished. M. De Blainville concludes by 

 observing that he had seen a drawing, by M. Laurillard, which had 

 been taken at Nice from one of these organised bodies while alive, 

 and that he supposed that it might well be a mass of eggs of 

 J/otfiwco. 



Relation* of the Acalephai to the other Inrtrtebrata. Mr. Huxley, in 

 his memoir before referred to, proposes to consider the AcaUphas in 

 some new relations. The presence of stinging hairs in these animals, 

 in common with the J/ydrotd, Sertularian, and Anthvwic Polyfics, 

 he regards as a fact of primary importance. He endeavours to show 

 that this fact, combined with the radiate polype form, and the compo- 

 sition of the body of two distinct meml mines, forms a very good 

 positive character for a group embracing the Hydroid and A iitlmznii 

 Polypa, and the Acalejihtt. He proposes to give the name ot 

 tophora. (' thread-bearers ') to this group, in allusion to the charac- 

 teristic presence of the ' thread-cell.' Frey and Leuckart had, how- 

 ever, applied the term Calenteraia to the same group. It will admit of 

 hiilNlivinion into two equivalent subclasses: one including the 

 id Polypes, the /i,,,!, win, 1'hyuophoridir, and Medunda, ii 

 which the stomach is not distinct from the common parietes, am 

 the reproductive organs are external; the other, embracing tin 



Anlkuznic Polypa and Berolda in which the stomach is distinct 

 from the common parietes, and the reproductive organs are internal 

 The author propones the terms Anaxioa and jEcioa for these 



two dni-iiuns. These groups mutually represent each other a. 



ollows : 



ASiCIOA. 



II i-.-i.i. 

 Corynidtr. 



Aetinidir. 

 XnnnthUlft. 



Xeduiidtc. 



On these grounds Mr. Huxley proposes to break up the class /. 

 of Cuvier into four groups. Supposing the Caienttrata to form a sort 

 of central group, we have, on the one hand, the Ateidian* and tin 

 Biyotoa leading to the Moltiucn ; on the oil,, r. the Ethwwderm* an. 

 the toK>a leading to the Annul***; whilst the Potygattria, 8p<mya 



Ascidiaos. Bryozoa. EchinoderoaU, Entosoa. 

 RADIATA. 



C.KLENTKHATA. 



Antccioa. JKcia*. 

 I'olygmstrica, Spongiadto. Orcgarinnda;. 



Fossa IMI-RESSIOSS or MKDCS.KI 



Mr. Babbage, in his paper ' On Impressions in Sandstone resembling 

 those of Horses' Feet,' December, 1886, in which he n..ti.c.l those in 

 the channel of a stream on the extensive moor calleil 1'wll-y-Uuon, 

 about seven miles from Merthyr Tydvil, to which his attx-nti.m wim 

 drawn by Mr. Quest of Dowlois, and the analogous ca8t in the <].! 

 red-sandstone of Forfarehire, there called Kelpies' Feet, de.~ 

 some observations made by Sir C. Lyell, on impressions left. !> 

 MedvMC on the rippled sand near Dundee. On removing the K<'1"U- 

 nous body of the animal, a circular space was exposed, not ripple.!, 

 but having aroutnl half the lioriUr a ilepression of a 1'orni. 



These marks, howev.T, wfreiiot ron.-*iiliM' l.yrll a- i<l 



with those called Kelpies' Feet, but merely HO tar analogous as to 

 invite further observations, and to make ii t.. ]>OBSOSS 



drawings of the impreaxions which different species of Medtuie leave 

 when thrown by the tide upon a beach of soft mud or ui(L (' GeoL 

 Proc.,' vol. ii.) 



ACANTHA'CE., an order of plants belonging to the Monopeta- 

 lous division of DicolyUdant. Its type is tin ,<ihus. The 



species are herbaceous or shrubby ; they arc extremely nuiiiiion in 

 every tropical country. Many of the species arc mere wtxxls; others 

 bear handsome flowers with gaudy colours, but seldom with any 

 odour; a very small number have been occasionally eni] 

 medicinally as emollients or diuretics. 



The roots of Acanthaeue are either annual or perennial. The 

 stems are usually four-cornered when young, but a!' income 



nearly round ; their inside is occupied by a largo proportion of pith, 



ca,,tk<m. 



which is enclosed in a thin layer of imperfectly fortu, 1 wood : an.l at 



each joint then- is a slight "tumour with an articulation, by which 



they are rraulily know ;, ,sV-,-.,;,/,/.. 



Their flowers are often enclosed within 1 



bracts(l). Th calyx (2) UtwuJly composed of i .rtie|arU, 



which overlaji each other, and occasionally grow together at, the 



base. The mr,>lla(:5HHmom>italoiw and irregular. The stama 



are either two or tour, but in the latter case are of unequal lengths. 



The pistillum (6) in nui>crior and turcillod. The e. 



tains two cell.-, which burst when ripe, often with elasticity, and 



expose a few roundish seeds hanging to the cells by cur 



I.,-..,. .. -. 



The stems of all the species emit rooU very readily from 

 tun. id arti, .,!;. lion* ; on which account gardener* universally 1 

 them by cuttings of the full-grown branched. They Mr,- always easy 

 to cultivate, provided they are not kept in to ..... 1<1 or too dry a 

 situation. The annual kinds freely produce seeds, by which they are 

 readily multiplied. 



most common genera are /( i<Ui,Tli.,,i 



anlkemiun, Lankaterio, and / 



(Iti-own 1 * i;,:ilromiu Florce Jfor [Itttiatiduf; Bartlmg's On 



1,1 l.indlev's Introdv 



Esenbeck's Krpotition, in the third volume of Dr. Wollich s Planta 

 Atiatica Rarium.) 



ACA'NTHIdX, in Zoology, a genus of/.' tabUshed by 



M V Cmier. and einl.raring two 3 K""wn. at 



present, by their osteology. In the number and form of their teeth, 



