It has, therefore, been suggested by these authors that the classification of the Malacostraca should be revised, and Calman (_loc. cit._) has brought forward the following scheme:— The division PERACARIDA, including the Eucopiidae, Lophogastridae, and Mysidae (= Mysidacea), the Cumacea, Isopoda, and Amphipoda, is characterised by the fact that when a carapace is present it leaves at least four of the thoracic segments free and uncoalesced: by the presence of a brood-pouch formed from the oostegites on the thoracic limbs of the female: by the elongated heart: by the few and simple hepatic caeca: by the filiform spermatozoa: and by the direct method of development without a complicated larval metamorphosis. The biting face of the mandible has a movable joint, the “lacinia mobilis.”[89] The division EUCARIDA, on the other hand, including the Euphausiidae and the Decapoda, shows the converse of these characters. The carapace coalesces with all the thoracic segments, there is never a brood-pouch formed from oostegites, the hepatic caeca are much ramified, the heart is short, the spermatozoa are spherical with radiating pseudopodia, the development is indirect with a complicated metamorphosis, and the mandible is without a lacinia mobilis. Corresponding divisions are made by Calman to receive the other Malacostraca, namely, the PHYLLOCARIDA for _Nebalia_, the SYNCARIDA for _Anaspides_, and the HOPLOCARIDA for the Stomatopoda or Squillidae. The important array of characters which separates the Euphausiidae from the other Schizopods and unites them with the Decapoda can no longer be neglected, and the consideration of _Anaspides_ and its allies will further emphasise the extreme difficulty of retaining the Schizopoda as a natural group. In the sequel Calman’s proposed scheme will be adopted. DIVISION 1. SYNCARIDA. There is no carapace, and all the eight thoracic segments may be free and distinct. Eyes may be pedunculate or sessile. The mandible is without a lacinia mobilis. There is no brood-pouch, the eggs being deposited and hidden after fertilisation. The spermatozoa are filiform, the hepatic caeca very numerous, and the heart tubular and elongated, with ostia only in one place in the anterior thoracic region. The auditory organ is at the base of the first antennae. =Order. Anaspidacea.= =Fam. 1. Anaspididae.=—The mountain-shrimp of Tasmania, _Anaspides tasmaniae_, was first described by Thomson[90] in 1893 from specimens taken in a little pool near the summit of Mount Wellington; it was redescribed by Calman,[91] who drew attention to its remarkable resemblance to certain Carboniferous fossils of Europe and N. America (_Gampsonyx_, _Palaeocaris_, etc.).