254 



HARDWICKE'S SCIENCE-GOSSIP. 



marked all over, below and above, with sinuous 

 worm- tracks. These cliffs rise sheer out of the green 

 Atlantic to a height of three hundred feet, and appear 

 •to be of the same character throughout. Everywhere, 

 where it is possible to examine them, the thin flags 

 are crowded with these peculiar markings. People 

 who have been to the celebrated quarries in the 

 same geological formation near Kirby- Lonsdale, will 

 have observed the flags impressed in a similar way. 

 We give a sketch of them as they appear in a hand 

 specimen. As these Kirby-Lonsdale flags are much 

 in demand by house builders in the north, and there- 

 fore get widely distributed, some of our readers may 

 have seen them a long way from their parent quarry. 

 The commonest of these worm-markings is Crosso- 

 podia. In Penwhapple Glen, Girvan, Ayrshire, 

 many species of worm-tracks have been recognised, 

 belonging to Nereites, Myrianiies, Crossopodia, Nemer- 

 titcs, etc. ; annelid markings are also found in the 

 shales at Moffat. A peculiar kind of worm-track, 

 called Cymadcrina, is left on the surfaces of the Lower 

 Carboniferous rocks near Settle, in the Valley of the 

 Ribble. 



No doubt most, if not all, of these tracks were made 

 by worms like our common Nereis. This had long 

 been suspected before Dr. Hind, by dint of great 

 patience, discovered annelid jaws in the Silurian 

 rshales at Ludlow, Much Wenlock, Iron Bridge, 

 Stoke Edith, and elsewhere. These are figured in 

 his paper on the subject read before the Geological 

 Society. The largest of the annelid jaws he found 

 so plentifully did not exceed one-fifth of an |inch. 

 Dr. Hind has proved that these jaws differed as much 

 among themselves so far back as the Silurian period 

 as they do now — a plain indication of the antiquity 

 •of the tribe. 



Worms which form tubes cannot of course make 

 ■tracks, but they leave evidences of their existence 

 behind them in the fossil tubes they once inhabited. 

 These sometimes form strata of no inconsiderable 

 thickness. Indeed, any geological student who has 

 visited the seashore of St. Bee's, Cumberland, at low 

 water, will have noticed extensive beds formed solely 

 of the cemented sand-tubes of modern species of 

 Sabellaria. Sahellaria and Terehella are very common 

 tubed worms in British seas, both of them constructing 

 sand-cemented tubes. The latter is always abundant 

 where there is a hard, clayey sea-bottom. It is rarely 

 that we get these worm tubes fossilised, as they tend 

 to fall into their component grains of sand when the 

 worms die. 



With the hard, calcareous tubes of such species of 

 sea-worms as Serpida and its kind, we have no] diffi- 

 culty. This form of annelid has had perhaps a more 

 stereotyped or stable form of existence than any 

 other creature in the world. There is no ostensible 

 difference between many Silurian tubed worms and 

 those now in existence. The pretty little Spirorbis 

 found in the Upper Silurian rocks has had a continu- 



ous and unchanged existence through every geolo- 

 gical period until now. We find it attached to fossil 

 shells and coral beds in the Silurian and Devonian 

 limestones. Fourteen species occur in the Carboni- 

 ferous rocks, some of them found adhering to the 

 trunks of Sigillaria and almost encrusting them, just 

 as we find them adhering to the larger sea-weeds 

 along our shores. Under the names of Serptdites, 

 Cormilites, Tentacitlites, CouchioUtes, etc., the sea of 

 every geological period has abounded in tubed worms. 

 The Wenlock limestone literally swarms with these 

 tapering elegant tubes, ringed like the tentacles of 

 insects, and hence called TcntacuUtes. This is a type 

 of what is called a //vv worm- tube, i.e., one that is not 

 attached to shells or rocks, like the modern Serpida. 

 Formerly it was regarded as a pteropod mollusc allied 

 to Ilyale. Cormilites is another genus nearly related 

 to it, and both are characteristic of the Silurian for- 

 mation. The chief species in the latter rocks is 

 Cormdites serpulariiis. It is frequently found as 

 much as three or four inches in length, ringed, 

 and gradually tapering to a point. Casts of this 

 species of worm tube frequently occur, and the young 

 student might be easily misled by them into thinking 

 it was a different fossil to the Cornulites found with 

 its external shape ; for this internal cast is in a series 

 of sharply marked off segments, one within but less 

 than another, like the fully drawn-out parts of an old- 

 fashioned telescope. This species is very abundant in 

 the Woolhope beds. Ortoiua (named after Professor 

 Orton) is a genus of abundant annelid tubes, also free, 

 which is peculiar to the Upper Silurian rocks of North 

 America. Tentacidites anmdatus is the commonest 

 of our British species ; 71 ornatus being perhaps [the 

 prettiest. The former is more abundant in the Lower 

 Silurian rocks at May Hill, and elsewhere, and the 

 latter in the Upper. The Wenlock shales are very 

 rich in fossil-worms, Mr. Etheridge recording no 

 fewer than thirty-five species of all kinds, Dr. Hind 

 having added twenty-four. Among the characteristic 

 forms of these beds are Trachyderiiia and Aranellites. 

 No doubt there were ancient sea-worms resembling 

 Serpula, and it is possible some may have been inter- 

 mediate between it and the modern SabcUa, which latter 

 is possessed of a leathery tube, often strengthened by 

 adhering sand-grains. Thus, in the Upper Silurian 

 rocks about Ludlow we meet with numerous traces of 

 a thin calcareous worm-tube, transversely striated, and 

 very ribbon-like, called Serpidites longissimus. Trachy- 

 dcrma coriacca is still more like a Sabella tube 

 stiffened by a deposit of lime. Scoliodcrma serpidites 

 is found in the rocks of the Wrekin and in the 

 holly bush sandstones near Malvern. Serpidites 

 dispar is abundant about Ludlow, and also in the 

 Upper Silurian rocks near Kendal ; and the student 

 will find a capital collection of them in the museum 

 of that town. A more delightful neighbourhood for 

 fossilising than Kendal can hardly be found in Eng- 

 land, or a more varied one. We have seen Serpidites 



