THIRD DIVISION, CLASSES— CRUSTACEA, ARACHNID A, 



AND INSEGTA. 



CRUSTACEA. (P. 407— 448.) 



The British Malacostracous Crustacea form the subjects of two valuable works ; one, by Dr. Leach, in quarto, 

 with beautiful coloured plates, representing each species of the natural size ; and the other now in course of pub- 

 lication by Professor Thomas BeU, forming part of Mr. Tan Voorst's beautiful series of works upon British 

 Natural History. 



An invaluable series of illustrations of the whole of the class Crustacea, has been published by Milne Edwards, 

 in the Crochard edition of the Regne Animal. 



The Crustacea of D'Orbigny's Voyage have also been more recently described and beautifully figured by MUno 

 Edwards, and those of the voyage of the Samarang, by Mr. A. Whits (now in course of pubhcation). Other new 

 species have also been described by Mr. White in detached papers in the Annals of Natural History. 



The periodical casting of the shell by these animals after their arrival at their adult form, led to the long-received 

 opinion that they had not previously xmdergone any decided metamorphosis. The recent investigations of several 

 authors have, however, clearly proved that the young fry in many species are quite unhke their parents, and that in 

 fact they are the animals which had been previously considered as distinct Entomostracans, under the name of 

 Zoea. It is singular, however, that the fry of the common Cray-fish (as observed by Rathke), and of the land Crabs, 

 do not materiaUy diifer from the adult state. 



A new and remarkable genus, named Calocaris by Professor Bell, belongs to the Decapod Macrom-a and subsection 

 Astacini (p. 420), but with elongated limbs, a very thin crust to the body, destitute of all colouring pigment, and of 

 cornea; in the eyes. C. Macandrefe, a species found in Loch Fyne and the Mull of Galloway, inhabits a depth 

 of no less than 180 fathoms, where of course distinct vision would be useless and unavaihng, wliich accounts for the 

 rudimental character of the eyes, which are entirely white. 



Dr. Erichson has recently published a memoir on the genus Astacus (p. 420), describing a number of additional 

 species of Cray-fish from various parts of the world. 



Several other new and interesting British genera allied to Mysis (p. 422), have been described by H. Goodsir in 

 the New Edinburgh Philosophical Journal. 



Zeuxo, Templeton in Trans. Ent. Soc. (Z. Westwoodiana) ; and Crossiirus and Liriope of Rathke (Nova Acta, Vol. 

 XX.) are small but remarkable genera closely allied to Rhnea, p. 428. 



Many additional species as well as several new genera of Amphipoda (p. 429), have also still more recently been 

 described by Rathke, in Nova Acta, Vol. XX., and in Kroyer's Tidsskrift ; and in a very interesting genus named 

 Clielura terebrans, which burrows into submerged wooden structures in the same manner as Limnoria, has also 

 been described by Philippi in the fourth Volume of Wiegmann's Arcliives. 



H. Goodsir has also added some new and very distinct British species of Amphipods in the Edinburgh New Philo. 

 sophical Journal, Vol. XXXIII. 



H. Goodsir has described a third species of Bopyrus (p. 431) in the Annals of Nat. Ilist., Vol. XV., found beneath 

 the carapace of Ilippolyte ensiferus; and Rathke has described and figured, with all its details, a new allied genus 

 named P)iry.\us, also found beneath the shells of diiferent Macrourous Crustacea (Nova Acta, Vol. XX.) of which I 

 possess a British specimen. 



A very elaborate paper upon the destructive Limnoria terebrans (p. 432), has been published by Dr. Coldstream 

 in the scventeentli volume of the Edinburgh New Philos. Journal. 



Two additional British species of Arcturus (p. 433), have also been described by 11. Goodsir. 



The development of the eggs and young of Asellus aquaticus (p. 433), has formed the subject of a very elabo- 

 rate memoir by Rathke, published in the second volume of the second scries of the Annales des Sciences Natu- 

 r ell eg. 



II. Goodsir has described several new British species of the singular genus Cuma (p. 437), as well as two new 

 and allied genera, named Bodotria and Alauna, in the thirty-fourth volume of the Edinburgh New Philos. 

 Journal. 



Dr. Baird's Papers on different portions of the Entomostraca, published in the Annals of Natural History, must 

 be consulted, and also a paper by the same gentleman, in the first volume of the Zoologist, upon other species 

 which are luminous, and inhabit the ocean ; including tlic genera Oithona and Cyclopsina. Amongst the minute 

 luminous oceanic species, and probably, in the present order of Branchiopoda, must also be ranged the genus 

 Sapphirhia of Edwards, as well as several other minute species and genera recently described by Goodsir, pecu- 

 liar for possessing a double eye in a single dark spot, with the body depressed as in the Isopoda, and the posterior 

 thoracic legs double. They arc very active in their habits, and svvim about in company witli other allied forms. 

 They constitute the genera Zaun, SUrope, and CarUlus. The Oniscus fulgcns of Tilcsius seems to belong to the 



