152 DISTRIBUTION OF THE NEMERTEANS. 



Zetlandic seas. Carinetta annulata stretches from the north of Shetland to the Mediterranean, 

 and a very similar species is found at the Cape of Good Hope. 



Others, again, have a more southerly range, and have not yet been found in the northern 

 portions of the British Islands ; but on this point I would not speak dogmatically, for very much 

 yet remains to be done in regard to the distribution of marine animals. A. spectabilis, Borlasia 

 Mizabetlice, and Micrura aurantiaca may be instanced as specially southern forms. 



Some of the Nemerteans live at a depth of many fathoms and at a considerable distance 

 from land, as well as between tide-marks, for example, Nemertes JVeesii, Zineus marinus, and 

 bilineatus, Micrura purpurea and Carinetta annulata. Amphiporus pulcher and Cerebratulus 

 angulatus are rarely found elsewhere than in deep water, the limits being from 5 to 120 

 fathoms. Amongst the Nemerteans procured in the dredgings of the " Porcupine" in 1869 and 

 1870, no new form, so far as can be ascertained from the spirit-preparations, occurs. It is 

 interesting, however, to notice that the Anopla much exceed the Enopla in number, the most 

 abundant form being Micrura fusca, with its flattened and oar-like posterior extremity. Tetra- 

 stemma Candida, again, was found at a depth of 420 fathoms, its usual site being the laminarian 

 and litoral regions. Representatives of the Anopla come from the great depth of 795 fathoms 

 off the coast of Portugal. The Planarians accompany them in these sites, and there is no reason 

 why both should not be found at yet greater depths. A. lactifloreus, all the Tetrastemmce, 

 ProsorhochmuSy Nemertes carcinopkila, many of the Linei and Micrura, and Cephalothricc, have 

 their habitat between tide-marks, though sometimes at the extreme border of the litoral zone ; 

 indeed, as a rule, Tetrastemma dorsalis is a laminarian form. 



M. de Quatrefages states that he has seen imprints in the rocks of Solenhofen and 

 Strasbourg, which he thinks belong to Nemerteans, in the latter case especially to the " genus 

 Borlasia;' and palaeontologists have expressed similar opinions. The fossils in the lithographic 

 stone of Solenhofen recently noticed by Prof. Ehlers 1 under the name Legnodesmus bear a close 

 resemblance to such as might be caused by the Nemerteans ; but a perusal of his excellent 

 descriptions and drawings leaves an impression so indefinite that further and more extensive 

 investigations are evidently necessary before a safe decision can be arrived at. The most 

 interesting part of this paper is the account of his finding stylets in the Legnodesmus figured in 

 taf. xxxvii, figs. 1 and 2. My acquaintance with the living animals leads me to entertain doubts 

 as to their connection with the so-called fossil Nemerteans (Nemertites) of the Cambrian rocks ; 

 at least, those coils I have seen suggest the following ideas : — Since they are simply casts without 

 organic remains, the worms which made them could only have done so in shallow water, so as to 

 have raised the snout to the surface, and crawled off in the usual manner (by floating). Any 

 other mode of departure would have blurred the tracks in a deposit so soft as to receive such 

 impressions. Moreover, I have often observed similar contorted tracks in the soft muddy sand in 

 tidal pools — tracks made by litoral univalves in their daily wanderings. 



1 c 



Ueber fossile Wiirmer aus dem lithographischen Schiefer in Bayera/ Cassel, 1869. 



