DIODONTA. 



DIOPSIS. 



354 



which M. de Blainville is stated to have rested for the cetaceous 

 character of Dinotherlum, appears to us to be rather meagre and 

 hardly sufficient to warrant the conclusion. At present the extremi- 

 ties of this creature have not been found. They would undoubtedly 

 throw more light on its true character than the skull alone can do. 

 In the British Museum is the femur of an animal from Epplesheim, 

 supposed to belong to the Dinotherium. If this point could be 

 satisfactorily determined it would at once clear up the difficulty, and 

 constitute the Dinotherium a terrestrial species. 



DIODONTA. [TELLINID.E.] 



DKECIA, the twenty-second class in the artificial method used by 

 Linnaeus in arranging plants. It comprehends such genera as have 

 male or stamen-bearing flowers on one plant, and female or pistil- 

 bearing flowers on another, as willows. Hence all plants having the 

 sexes thus distinguished are called dioecious. 



DIOMEDEIN^E, a family of llirda to which the Albatrosses belong. 

 The characters of the genus Dionudea are given under ALBATROSS. 

 In that article three species of this genus are referred to. We now 

 give a complete list of the species of this important genus : 



Diomedea exniam, Linn. This bird is abundant between 30 and 

 60 S. lat., and equally numerous in all parts of the ocean bounded 

 by those degrees ; its range however extends much farther south, 

 even to within the antarctic circle. 



D. melanophrys, Temm. It is the most abundant species of the 

 southern seas ; equally numerous in every part between the 30th and 

 60th degrees. 



D. cauta, Gould. This species was procured by Mr. Gould off the 

 south coast of Van Diemen's Land. 



D. chlororhynchoi. Lath. It occurs between 30 and 60 S. lat., in 

 both the Atlantic and Pacific Oceans. 



D. culminata, Gould. This bird is rather abundant both in the 

 Pacific and Atlantic Oceans, between 30 and 50 S. lat. 



// fttlif/inosa, Gmel. It occurs in all parts of the ocean between 

 30 and 60 S. lat. ; equally common off Van Diemen's Land, Cape 

 Horn, and the Cape of Good Hope. 



D. brackyura, Temm. Found hi the North Pacific Ocean. 



D. gilbota, Gould. An inhabitant of the North Pacific Ocean. 



D. olivaceorfiync/ia, Gould. China seas (?). 



Mr. Gray,inhis 'Genera of Birds,' also gives D. spadicea as a species. 

 He also makes D, gitibosa (Gould) synonymous with D. nigripa, 

 Audubon, 'Orn. Biog.,' voL v. p. 327, and adopts the latter name as 

 having the priority. 



DION. [CYCADACE.K.] 



DION^EA, a most singular genus of herbaceous Plants belonging 

 to the natural order jDroftracea. There is one species, the D. mutci- 

 pula, which is remarkable for the irritability of its leaves, which, 

 when brushed against by an insect, will suddenly close upon it and 

 hold it fast, whence it is often called Venus's Fly-Trap and the Caro- 

 lina Catchfly Plant. It is botanically related to the Droiera, or 

 Sundew, which has also the property of seizing insects by its viscid 

 hairs, but differs so much as to have led some botanists to doubt 

 whether it really belongs to the same natural order. Its flower- 

 branches, for example, are not rolled up before they unfold, but have 

 a straight aestivation ; the placenta) of the fruit are stationed at the 

 base of the one-celled capsule ; the stigma is a lacerated fringed brush, 

 and there are other differences ; but upon the whole it is probably a 

 genuine portion of the Droseraceous Order. 



iJiontfa has broad stalked leaves, spreading in a circle round the 

 bottom of the flower-stem. Its flower-stem rises straight to the height 

 of 6 or 8 inches, and is terminated by a cyme of small greenish-white 

 flowers, each of which has a calyx of 5 sepals, 5 wedge-shaped 

 notched petals, 10 hypogynous stamens, and an ovary shaped like 

 ome of the old German wine-bottles, round at the bottom, and taper- 

 ing suddenly into a short neck or style. The best modern account of 

 its habits has been given by Mr. M. A. Curtis, who thus speaks of it 

 from hi observations upon the plant in its native bogs: "The 

 IHiiiitrn muicipula is found as far north as Newborn, North Carolina, 

 and from the mouth of Cape Fear River to Fayetteville. It is stated 

 moreover to grow along the lower branches of the Santee, in South 

 Carolina ; and it is not improbable that it inhabits the savannahs, 

 more or less abundantly, from the latter place to Newbern. It is 

 found in great plenty for many miles around Wilmington in every 

 direction. The leaf, which is the only remarkable part, springs from 

 the root, spreading upon the ground at a little elevation above it. It 

 is composed of a broad stalk, like the leaf of an orange-tree, winged, 

 and from 2 to 4 inches long, which at the end suddenly expands into 

 a thick and somewhat rigid blade, the two sides of which are semicir- 

 cular, about two-thirds of an inch across, and fringed round their edges 

 with somewhat rigid cilia', or long hairs, like eye-lashes. The leaf 

 indeed may be aptly compared to the two upper eyelids, joined at 

 their bates. Each portion of the leaf is a little concave on the inner 

 side, where are placed three delicate hair-like organs, in such an order 

 that an insect can hardly traverse it without interfering with one of 

 them, when the two sides suddenly collapse and inclose their prey, 

 with a force surpassing an insect's attempts to escape. The fringe or 

 hair* of tin- |ipi>.-iiti> .*ides interlace, like the finger* of the two hands 

 clasped together. The sensitiveness resides only in these hair-like 

 procemes on the inside, as the leaf may be touched or pressed in any 



WiT. HI8T. DIV. VOL. II. 



other part without sensible effects. The little prisoner is not crushed 

 and suddenly destroyed, as is sometimes supposed ; for I have often 

 liberated captive flies and spiders, which sped away as fast as fear or 

 joy could hasten them. At other times I have found them enveloped 

 in a fluid of mucilaginous consistence, which seems to act as a solvent, 

 the insects being more or less consumed by it. This circumstance 

 has suggested the possibility of the insects being made subservient to 

 the nourishment of the plant, through an apparatus of absorbent 

 vessels in the leaves. But as I have not examined sufficiently to pro- 

 nounce on the universality of this result, it will require further 

 observation and experiment on the spot to ascertain its nature and 

 importance. 



" It is not to be supposed, however, that such food is necessary to 

 the existence of the plant, though, like compost, it may increase its 

 growth and vigour. But however obscure and uncertain may be the 

 final purpose of such a singular organisation, if it were a problem to 

 construct a plant with reference to entrapping insects, I cannot con- 

 ceive of a form and organisation better adapted to secure that end 

 than are found in the Dioruea mmcipula. I therefore deem it no 

 credulous inference that its leaves are constructed for that specific 

 object, whether insects subserve the purpose of nourishment to the 

 plant or not. It is no objection to this view that they are subject to 

 blind accident, and sometimes close upon straws, as well as insects. 

 It would be a curious vegetable indeed that had a faculty of distin- 

 guishing bodies, and recoiled at the touch of one, while it quietly 

 submitted to violence from another. Such capricious sensitiveness is 

 not a property of the .vegetable kingdom. The spider's net is spread 

 to ensnare flies, yet it catches whatever falls upon it ; and the ant-lion 

 is roused from his hiding-place by the fall of a pebble ; so much are 

 insects also subject to the blindness of accident." 



We may add, with reference to the American author's conjecture 

 that the trapped insects may contribute to the nourishment of the 

 leaf of Diontra, that leaves have actually been fed with chopped 

 meat, and have been found to become more healthy and vigorous in 

 consequence of this artificial stimulus ; but still no argument can be 

 drawn from this fact in favour of the supposition that the plant 

 catches flies for nutriment, as most plants would be benefited by 

 such treatment. 



DIOPSIDE. [AcoiTE.] 



DIO'PSIS, a genus of Dipterous Insects of the family Sepsida:. 

 The insects of this genus are remarkable for the immense prolonga- 

 tion of the sides of the head. The head itself is small, and appears 

 as if it were furnished with two long horns, each having a knob at its 

 apex ; these horn-like processes however are not analogous to the parts 

 usually termed antennae, but are in fact prolongations of the sides of 

 the head, the knob at the apex of each being the eye of the insect. 

 They vary in length according to the species. In some they are 

 almost equal to the whole length of the insect, whereas in others 

 they are only about half that length. The antenna; are situated close 

 to the eyes, and are three-jointed : the basal joint is the smallest and 

 is very short ; the terminal joint is the largest, of a globular form 

 (or nearly so), and furnished towards the apex with a simple seta; 

 there is also a short seta on the peduncle or eye-stalk, situated about 

 midway between the base and the apex of that process, and on the 

 anterior part. The thorax is somewhat attenuated anteriorly, but 

 approaches to a spherical form, and is generally furnished with two 

 spines on each side ; the scutellum is also furnished with two spines. 

 The body is more or less elongated, sometimes nearly cylindrical, but 

 generally increases in diameter towards the apex. The legs are toler- 

 ably lu.ig the anterior femora are generally thick, and furnished 

 beneath with minute denticulations, and the four posterior femora 

 are often furnished with a spine at their apex. 



Vioptis Sykesii. G. li. Gray. 

 a denotes the natural size. 



The illustration represents the Diopsis Sykesii, one of the largest 

 species of the genus, and which has been selected as possessing the 

 longest eye-stalks ; these processes in this insect are of a pitchy red 

 colour, and the body is of the same tint. The head and thorax are 

 black, and the wings are clouded with brown. 



But little is known of the habits of these insects. Colonel Sykes, 

 who collected great numbers of the above species during his residence 

 in India, furnished Mr. Westwood with the following notice respecting 

 their habitat and habits : 



"Habitat. The hill fort of Hurreechunderghur, in the western 



2 A 



