162 



KNOWLEDGE. 



[Jdly, 1901. 



warded their captor witli " une odeur tres mauvaise et 

 tres penetiante.' 



The grub of Micralymma is more lively than its parent 

 beetle. It is elouyate in form, with the legs short, stout. 

 and spiny; the tubular process at the hinder end can 

 be bent downwards to act as a false-foot or pro-leg 

 (Fig. 9). The pupa is a most wonderful creature, with 

 its armature of long bristles that doubtless serve to en- 

 tangle air-bubbles for breathing (Fig. 10). 



As might be expected, the Ground-beetles (Carabidse)— 

 those active, predaceous, swift-running insects, which lurk 

 commonly under stones and in such places — are well re- 

 presented by the sea-shore. Space would fail us to 

 enumerate the sand-dwelling Ground-beetles that may 

 be met with above high-water mark. Several kinds of 

 Dyschirius, for instance, small, dark, shining bron?y 

 beetles, with the fore-shins flattened and strengthened 

 to serve for digging, abound on our coasts. They burrow 

 into the sand in pursuit of the Rove-beetles of the genus 

 Bledius mentioned above and ruthlessly devour them. 



There is a large group of small Ground-beetles — the 

 Bembidiiua — which frequent damp places, and are in- 

 deed semi-aquatic in their habits. The most character- 

 istic structural feature of this group, the vei-y shoi-t and 

 pointed terminal segment of the second maxillary (labial) 

 palp (Fig. 11, L. p.), is found also in the Haliplid», that 

 family of true water-beetles which is most nearly allied 

 to the Cax-abidfe. The very niunerous species of Bem- 

 bidium are the delight of the specialist, and the despair 

 of the average beetle-collector. Several of them may be 

 found on the sea-shore, but they seem to keep out of the 

 . reach of the tides. There is an allied genus, how- 

 ever — Lymnaeum — a species of which, L. iilr/ropiceum. 

 Marsh, occurs locally on the south coast of England and 

 in the Isle of Wight, lurking under stones and shingle, 

 below as well as above high-water mark. This little beetle 

 inhabits also the French coast and the shores of Dalmatia 

 and the Crimea. The most remarkable discontinuous 

 range of this species is analogous to that of its genus 

 which occurs in Europe, the East Indies. California, and 

 the Kurilo Islands near Japan. 



Fig. 11. — Cilleniis lateralis. M;igni6od 10 lime?. L, sfcond 

 maxillffi (labium), magnified 20 times, (p, palp.) 



Still more specialized for a marine life is CiUenus 

 lateralis, Sam. (Fig. 11), the only species of its genus, 

 distinguished from Bembidinm by its relatively shorter 

 feelers and parallel-sided elytra, which ai"e of a pale, 

 sandy colour with dark markings, the large head and 

 fore-body being shining bronzy green. Cillenus occurs 

 at many points on the British and Irish coasts, some- 



times beneath stones, sometimes on the sand, but almost 

 always below high-water mark. Its continental i-aiigc 

 extends northwards only to Holland, but southwards as 

 far as Portugal and Morocco. It is remarkable that 

 while British specimens of this beetle are all wingless, 

 those from southern Europe are occasionally winged ; 

 evidently the species as a whole has not entii-ely lost the 

 power of flight. At low water numbers of Cillenus 

 may be found running in the sunshine; when the tide 

 rises they retire under stones, or dig holes between 

 one or two inches deep in the sand. In such shelters 

 they survive in safety their immersion twice every day. 

 A. H. Haliday, in the paper to which reference has 

 already been made, gives a vivid account of the habits 

 of Cillenus as observed by him on the Co. Dublin coast 

 in the year of Queen Victoria's accession. " They pi'ey 

 upon saiidhoppers (Talitrus), seizing them by the soft 

 part of the underside, and, in this way, are able to 

 master game many times their own bulk. Sometimes 

 three or four beetles may be found in concert, attacking 

 a saudhopper of the largest size. The tide retiring has 

 scarcely uncovered the sand when these little depreda- 

 tors are abroad from their hiding-places and alert in 

 the chase." The grub of Cillenus has been described 

 by Fairmaire. It has short legs and a very large head 

 with long, formidably toothed mandibles. 



Another group of Ground-beetles with marine repre- 

 sentatives are the Trechina — a tribe allied to the 

 Bembidiiua. but distinguished by the elongate terminal 

 segment of the labial palp (Fig. 13, L. p.). The species of 

 the large genus Trechus live mostly in dark concealed 

 situations, under stones, for example,' or in burrows along 

 the) banks of streams. One of them, T. lapidoxus, 

 Dawson, occurs just above high-water mark on the sea- 

 coast and along the shores of tidal rivers. But the 

 small beetles of the allied genus Aepus are perhaps 

 the most characteristically marine members of the whole 

 family, and, indeed, of the entire order of beetles. 



Small as these beetles are, 2 mm. (about yV inch) in 

 length, their aspett when seen with a moderate magni- 

 fication is striking and not easily forgotten (Fig. 13). 

 The relatively immense head, larger than the forebody 

 shield, and the truncate abdomen, broadest at its hinder 

 end and only partly covered by the wing-cases, give the 

 insect a Tiiost characteristic appearance. Both the 



European species of Aepus occur on the British and 

 Irish coasts. J. w^a/■(;«^^s■ (Stroem.) has a deep dorsal fur- 

 row on the forebody. and rather long parallel-sided wing- 

 cases, while A. Euhiiul. Laboulb., has an indistinct dorsal 

 furrow and shorter wing-cases widened behind. These 

 insects both qccur on the French and Spanish coasts, 

 and there is a third species on Madeira, and another far 

 away in Chile. They have not been found north of 

 Denmark, and it is remarkable that they seem to be 

 absent from the newest part of our own coast line — 

 from Yorkshire to Sussex, the region by which our 

 island was in Pleistocene times joined to the European 

 continent. While the I'ange of most of the shore- 

 haunting spring-tails points to an old continental coast- 

 line stretching from our area towards the north, that 

 of Aepus. and, as we have seen, of most of the marine 

 beetles, indicates the former extension of the old 

 land to the south and south-west. Aepus is clearly 

 a very ancient genus, and it is possible that these beetles 

 were amongst the first members of our present fauna to 

 reach our area, belonging as they clearly do, to the 

 south-western (Lusitanian) group, whose restricted dis- 

 tribution shows them to be the oldest animals surviving 

 in our islands. 



