NA TURE 



yNov. I, 1 88- 



aiea, such as Pectinura Iteros, OpJuoiiiusiuiii 7'aUduin, 

 nnd Asiroschcina arenosum, the first living near the 

 Celebes, the last two in the Carribean Sea. While 

 species differ thus much in the extent of their migra- 

 tions, there are certain bottoms where they seem 

 to decline to live at all. Thus in all the deep water 

 from the centre of the North Pacific to near the south- 

 west coast of South America, there was not a single 

 Ophiuran found. As to their distribution in depth, a 

 very large proportion live exclusively on the littoral zone, 

 and therein are included species both of cold and of hot 

 nater, tliough the number of the latter is much the larger- 

 Some fift) species live exclusively below looo fathoms, 

 and have to endure a degree of cold near to freezing, an 

 enormous water pressure, and an entire absence of sun- 

 light. 



The forty-eight, rather crowded, plates have been drawn 

 with skill and fidelity by Miss K. Pierson and Mr. L. 

 Trouvelot with the exception of Plate 48, which represents 

 half of an arm oi Gorgonoccphalus verrucosus, carried out 

 to its extreme twigs, and which stands as quite a monu- 

 ment of patience on the part of Mr. Lyman's assistant, 

 Miss Clark. 



The Second Report in this volume is by Prof. D. J. 

 Cunningham, on some points in the anatomy of Thyla- 

 cinus cynoccphalus, Phalangista maculata, and Phascogale 

 calttra, wdth an account of the comparative anatomy of 

 the intrinsic muscles and the nerves of the mammalian 

 pes. This Report gives details of the anatomy of three 

 little known mammals, representing types which differ 

 widely from each other both in physique and habits. A 

 special interest attaches to the anatomy of the Thylacine, 

 as it is rapidly becoming extirpated. In examining the 

 intrinsic muscles of the marsupial manus and pes, Prof. 

 Cunningham encountered a somewhat puzzling multipli- 

 cation of the elements. To clear this up and at the same 

 time to connect the condition with that found in other 

 animals he was induced to extend his inquiries upon this 

 point into mammals in general, and we are therefore 

 favoured with the results of this comparative research in 

 a very elaborate report on the comparative anatomy of 

 the mammalian foot. 



Vol. VI. contains also two memoirs : the first is a Report 

 on the Actiniaria, by Prof. Richard Hertvvig. As a con- 

 siderable number of specimens did not reach Konigsberg 

 until this Report was finished, we are promised a supple- 

 mentary report to describe these additional forms. Four- 

 teen plates accompany this Report. Beginning with a 

 detailed description of a typical .\ctinian, we have also 

 a comparative survey of the chief characteristics of the 

 several divisions and genera. Six tribes of Actiniana 

 are distinguished: (i) Hexactinia; ; (2) Paractiniae ; (3) 

 Monaulea; ; ().) Edwardsia; ; (5) Zoantherc; (6) Ceri- 

 antheae. Objecting to Verrill's assertion that all speci- 

 mens of ,'\ctini;e which are only known from preserved 

 specimens should be thrown away as of no scientific 

 value, Prof. Hertwig has laboured manfully over the 

 unfortunately rather badly preserved specimens of the 

 Challenger voyage ; and by keeping in view such factors 

 in their description as the structure of the tentacles, of 

 the septa, of the oral disk, of the circular muscle, &c., he 

 has presented a most minute and elaborate description of 

 an immense variety of new forms, the scientific value of 



which will go without dispute. As the. collections of the 

 Challenger were for the most part made in the open 

 oceans, the littoral zone, whicli would have furnished the 

 larger proportion of Actinia; was almost entirely neglected, 

 and but one littoral species occurs in the list. As a rule 

 the number of the Actinia; decreases as the depth in- 

 creases ; they have not been observed at a depth of over 

 2900 fathoms, but the greater the depth the more the 

 fauna w ts found to vary from that of the coast. Of the 

 twent5'-one forms from 500 to 3000 fathoms described, no 

 less than six species are found to have undergone some 

 extreme mdifications of their tentacles, whilst a like 

 phenomenon has never been observed in a single one of 

 the forms of the coast fauna, which greatly exceed the 

 deep-sea fauna in number. These alterations lie for the 

 most part in the direction of transforming the tentacles 

 into tubes and openings, and Prof. Ilertwig connects this 

 with the nutriment of these deep-sea forms, which is not 

 of a nature to be captured by tentacles. 



The Second Report is on the Tunicata, by Prof. Herd- 

 man. It is Part I., on the Simple Forms. The collec- 

 tion generally was found to be in a state of excellent 

 preservation, and consisted of eighty-two species, which 

 are referred to twenty genera. Of these, seventy-four of 

 the species and nine of the genera are new to science, but 

 it has not been found necessary to form any new families 

 The new genera are mostly instituted for very deep-sea 

 species. In several instances the new genera have been 

 of great interest, as they have demonstrated affinities 

 between known forms, and have exhibited combinations 

 of characters which in some instances necessitated a revi- 

 sion of the definitions of old genera, and even affected 

 one's ideas with regard to the characters of the families. 

 The new species are all beautifully illustrated in thirty- 

 seven plates. The memoir has prefixed to it a history 

 and bibliography of the group and a neat and well-written 

 account of its anatomy, which is accompanied by an ex- 

 cellent series of woodcuts. So little is known as to the 

 geographical distribution of the group that Prof. Herd- 

 man thinks any generalisation on this head would be of 

 little value. A few facts of interest are, however, men- 

 tioned : thus the Tunicata are greatly more numerous in 

 the southern than in the northern hemisphere, and they 

 reach a maximum of abundance in the far south. As to 

 their distribution in depth, the four families are found to 

 have the following limits : — 



The Molgiilid;E range from the shore to 600 fathoms. 

 The CynthiicUc ,, ,, 260a ,, 



The Ascidiidce ,, ,, 2600 ,, 



The Clavelinid.'c ,, ,, 129 ,, 



Seven species were found at depths of from 2000 to 

 3000 fathoms. 



Calcareous spicules are noticed as present in the tests 

 of several species of the genera Culeolus and Cjnthia. 

 They are very different in the two genera, being irregu- 

 larly branched and with smooth surfaces in Culeolus, 

 v.hile they are rod-shaped or fusiform, with their surfaces 

 minutely echinulated in Cynthia. Neither of the two 

 previously known genera in v.-hich the test is remarkably 

 modified— Rhodosonia and Chelyosoma — were collected 

 during the Challenger Expedition, but two of the new forms 

 show notable peculiarities in the test, Pachychlcena having 

 it greatly thickened all over, w-hile Hypobythius caly codes , 



