June 1 6, 1887] 



NATURE 



163 



10-13, are in open communication, forming a wide continuous 

 longiLudinal tube extending from somite 6 to somite 13. Open- 

 ings to the exterior from this tube were found in somites 6-9 

 inclusive, corresponding to the four large looped nephridia : 

 each of these openings was close behind the upper end of an 

 unciuigerous torus. The internal openings of the same four 

 nephridia could be traced with ease and certainty : they are 

 attached to the body-wall close behind the notopodial fascicles 

 of somites 5-8. These openings are wide, and are overhung 

 dorsally by a longitudinal lip furnished with a series of small 

 ciliated digitate processes : lower down, the anterior and poste- 

 rior lips of the opening are simple, thick-walled, and ciliated. 

 The aperture leads into a thin tube, which passes inwards and 

 backwards, curving round the inner end of the fascicle of bristles 

 behintl the aperture, and then, crossing the continuous tube, 

 passes up on the inner or medial side of the loop, at the apex of 

 which it is continued into the efferent wider limb of the loop, 

 which passes down on the outer side to open into the longi- 

 tudinal tube. Neither internal nor external openings could 

 be found in that part of the longitudinal tube which is 

 behind the loops : it seems evident that this part of the 

 tube represents four somewhat reduced nephridia which 

 have coalesced, but whose openings have disappeared. An- 

 teriorly to the four looped nephridi i are traces of three others : 

 the longitudinal tube extends forwards into somite 5 as if it 

 included a nephridium belonging to that somite, but I could find 

 no external opening in this somite : at the angle between the 

 septum behind somite 4 and the body-wall is a very obvious 

 nephrostome, which ought to lead into the longitudinal tube, 

 into that part of it corresponding to somite 5, but the connexion 

 could not be traced. Nephrostomes were also present attached 

 to the anterior face of the septa behind somites 2 and 3 (the first 

 and second branchiferous), and leading into tubes seen in somites 

 3 and 4, but I could find no external openings in these somites. 

 I could find nj nephrostome in somite i (the buccal) nor any 

 trace of a tube in somite 2. Gonads are present in the form of 

 clumps of deeply-staining small indifferent cells attached to the 

 iexterior of all the nephrostomata mentioned, seven in all. The 

 germinal cells, when still quite undifferentiated, separate from 

 the gonads, and undergo further development in the coalome. But 

 I found no reproductive elements in the cavity of the nephridial 

 system, though the body-cavity contained them in quantity, and 

 it is probable that at the right season they are expelled through 

 the nephridial system. The body-cavity contains, besides the 

 reproductive elements, a large number of spherical, vacuolated, 

 nucleated cells. This is the first case in which a communication 

 between successive nephridia has ever been discovered in any 

 adult invertebrate. It is true that in the development of Poly- 

 gordius, according to Hatschek, each nephridium gives off back- 

 wards a prolongation of itself, from which the next nephridium 

 is formed, and the two remain in communication for a time ; but 

 the connexion is soon severed, and in the adult the successive 

 nephridia are isolated and independent. In I.atiice conchilega 

 the nephridia have coalesced together after coming in contact 

 from before backwards, the separating membranes having dis- 

 appeared. The case is extremely interesting in the fact that we 

 have in it an approximation to the condition of the excretory 

 system in Vertebrata : the presence of a metameric series of 

 nephrostomata in vertebrate embryos has long ago been seen 

 to constitute a resemblance between them and Chaetopoda, but 

 hitherto no Chjctopod was known which resembled the verte- 

 brate in having a number of nephridia coalesced to form a 

 continuous longitudinal tube. 



It is surprising to find that, as far as I have been able to 

 discover, no resemblance to the condition seen in Lanicc conchi- 

 lega occurs in any of its near allies. The only species of the 

 genus Terebella as defined by Malmgren that occurs in the Firth 

 of Forth is Terebella Daniclsseni, but of this I have only one 

 specimen, and have not examined its nephridia. Of Amphitrite 

 there are two species in the Forth : Amphitrite cirrata I have 

 not examined, anatomically ; in Amphitrite Johnstoni there are a 

 large number ( 15-17) of nephridia forming long loops projecting 

 dorsal wards into the body-cavity, in the anterior region : each 

 has its own internal and e.xtemal openings, and is isolated and 

 independent. In Terebellides Streemii there is one pair of large 

 dark-coloured nephridia in the anterior end, and three pairs of 

 small rudimentary ones posterior to this. In Pectinaria 

 belgica there are three pairs : they are all independent. In 

 Melinna cristata there are several pairs, all separate. Figures 

 showing the interesting relations which exist in Lanice conchilega, 



together with a more complete description of the nephridia in 

 other forms of Polychreta, will I hope shortly be published in a 

 paper on the anatomy of Polychaita. 



NOTES ON THE GEOLOGY OF PART OF THE 

 EASTERN COAST OF CHINA AND THE 

 ADJACENT ISLANDS. 



CURGEON P. W. BASSETT-SMITH, R.N., has forwarded 

 ^ to the Hydrographical Department of the Admiralty a brief 

 Report on this area, embodying the results of ob ervations made 

 in the course of last summer during the cruise of H.M.S. 

 Rambler. Specimens of rocks were collected at certain points 

 on the mainland and on the neighbouring islands, stretching 

 from Chusan on the north to Ockseu Island, south of Hai-tan 

 Strait, opposite the northern part of Formosa. 



All the islands, with a single exception, appear to consist of 

 crystalline rocks. They usually present sharp rugged outlines, 

 with bold cliffs— more or less fissured and veined — -rising, in 

 many cases, vertically from moderately deep water. In the 

 following notes, the stations from which the specimens were 

 collected are described in succession from north southwards. 



Tou-wah Island, the most northerly station, consists of an 

 irregulur range of hills trending in a north-west and south-east 

 direction, and reaching an elevation of 1600 feet. A gray 

 granitic rock was obtained from the summit. Thornton Peak, 

 on the mainland in the province of Chi-kiang, separated from 

 the Chusan group by a narrow sea, is composed of a pink granite. 

 From Ta-fou Island, in San-moon Bay, a fine-grained purplish 

 quartz-felsite was obtained. The group of Hae-shan Isles seems 

 to be composed of a dark gray quartz-felsite, and a similar rock 

 forms the Tai-cho.v Islands. 



Another group of stations visited by the Rajnbler lies off the 

 coast of the province of Fu-kien. P"uh-yan Island consists of 

 hills reaching a height of 1700 feet, and yielding a fine-grained 

 greenish rock, apparently a diabase. Coney Island is composed 

 for the most part of a coarse pinkish granite, with veins of 

 quartz, and dykes which appear to consist of diabase and horn- 

 blende-porphyrite. The two islands known as Tung Yung are 

 formed mainly of quartz-felsite ; the specimens obtained from 

 the larger of the \.\\o isles containing much opaque white feldspar, 

 porphyritically distributed through the rock. In a cove at the 

 south-west end of the latter island, the rocks split up into 

 irregular columns, and in certain parts these columns exhibit 

 considerable curvature. 



The third group of stations is situated on the River Min, and 

 in the neighbourhood of its mouth. Chang-chi is a large irregular- 

 shaped island of red porphyrite. The island known as Matsou 

 is particularly interesting, the principal rock being a white 

 quartz-felsite, with a complicated network of basaltic dykes. 

 In a small sandy bay, a deep water-course exposes a layer of 

 dark earth, about a foot in thickness, crowded with land shells. 

 Two small neighbouring islands known as White Dog consist of 

 dark gray quartz-felsite. 



On the north side of the mouth of the River Min is an island, 

 termed Sharp Peak, about three miles in length, which culminates 

 in a rocky peak 1500 feet high. The island is formed, for the 

 most part, of a hard conglomerate, associated with slates and 

 shales, and with a talcose schist penetrated by veins of quartz. 

 A cliff at the north-east point of the island displayed a clear 

 section, in which this schist was seen to alternate with beds of 

 slate and conglomerate, inclined at about 45°. 



A small low island off the south point at the entrance to the 

 River Min, consists of granite, gneiss, and mica- schist. A 

 specimen of red granite, with crystals of iron pyrites, was ob- 

 tained from the rugged mountains of the neighbouring mainland. 

 Temple Point, on the north side of the Min, a few miles from 

 its mouth, yielded a greenish-yellow steatitic rock, with den- 

 dritic markings. At Pagoda Anchorage, up the river, a fine- 

 grained pink gneiss was obtained, and this locality also yielded 

 a fragment of a large crystal of smoky quartz. About twelve 

 miles further up the Yuen Fu branch of the Min River are some 

 hot springs having a miximum temperature, in November, of 

 114° F. The rock is here a quartz-felsite. An orthoclase 

 porphyry occurs about five miles further up the river, and quartz- 

 felsite again occurred ten miles higher. Here, in a curious 

 recess in the hill-side, in which a temple has been built, are 

 numerous stalactites, some of large size. The mountains all up 



