body, and bears behind three elegant sets of fine filamentous branchiae. The North American genus _Psephenus_ is placed in Parnidae, though instead of five, the male has seven, the female six, visible ventral segments; the larva is elliptical, with dilated margins to the body. Friederich, has given,[123] without mentioning any names, a detailed account of Brazilian Parnid larvae, that may perhaps be allied to _Psephenus_. FAM. 49. DERODONTIDAE.—_Tarsi five-jointed, slender, fourth joint rather small; front coxae prominent and transversely {245}prolonged; middle coxae small; abdomen with five visible segments, all mobile, the first not elongated._ One of the smallest and least known of the families of Coleoptera; it consists of four or five species of small Insects of the genera _Derodontus_ and _Peltasticta_, found in North America, Europe, and Japan. The distinction of the family from Cleridae is by no means certain; our European _Laricobius_ apparently possessing characters but little different. Nothing is known as to the life-histories. FAM. 50. CIOIDAE.—_Small or minute beetles; antennae short, terminal joints thicker; tarsi short, four-jointed; anterior and middle coxae small, oval, deeply embedded; abdomen with five ventral segments, all mobile._ The position of these obscure little Insects seems to be near Colydiidae and Cryptophagidae, though they are usually placed near Bostrichidae. So far as known, they all live in fungi, or in wood penetrated by fungoid growths. The cylindrical larvae live also in similar matter; they usually have the body terminated behind by one or two hooks curved upwards; that of _Cis melliei_ (Fig. 124) has, instead of these hooks, a curious chitinous tube. About 300 species of the family are now known; a score, or so, occurring in Britain. The Hawaiian Islands have a remarkably rich and varied fauna of Cioidae. [Illustration: Fig. 123—_Derodontus maculatus._ North America.] [Illustration: Fig. 124—_Cis melliei._ Martinique. A, Perfect Insect; B, pupa; C, larva; D, terminal portion of body of larva. (After Coquerel.)] FAM. 51. SPHINDIDAE.—This family of half a dozen species of rare and small Insects, differs from Cioidae by the tarsi being five-jointed at any rate on the front and middle feet, opinions differing as to whether the number of joints of the hind tarsi is four or five. These Insects live in fungi growing in wood, _e.g._ _Reticularia hortensis_, that are at first pulpy and {246}afterwards become powder. The larvae of both of our British genera, _Sphindus_ and _Aspidiphorus_, have been described by Perris, who considers them allied to the fungivorous Silphidae and Latridiidae. The systematic position of these Insects has been the subject of doubt since the days of Latreille.