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Caiman, Peripandalus de Man, Pandalopsis {h. M.-Edw.) Bate, Pantonms A. M.-Edw., Plesionika 



Bate, Parapandalus Borr., Heterocarpus A. M.-Edw., Dorodotes Bate, Chlorotocella Balss and 



Chlorotoais A. M.-Edw. The species of the genus Pandahcs Leach, about 20 in number, though 



some may prove to be synonyms, are found either north of the tropic of Cancer or south of 



the tropic of Capricorn and have not yet been observed between the tropics. The majority of 



the species of this genus are found in the North Adantic and in the North Pacilic, but do not 



occur in the Mediterranean, while only four are known from the southern hemisphere. The genus 



Dichclopandalus Caull., which is closely related, includes two species, one in the eastern, the 



other in the western half of the North Atlantic, the latter, however, has also been observed 



off Shumagin Bank, Alaska. The only species of Pandalina Caiman ranges, in the northeast 



Atlantic, from the Barents Sea to the Mediterranean. The genus Peripandalus de Man is also 



represented only by one species, Pci-ip. serratus (A. M.-Edw.) from Upolu, Samoa Islands. 



The six or seven representatives of the genus Pandalopsis (A. M.-Edw.) Bate, that differs from 



the other genera by the conspicuous laminar e.xpansion at the inner border of the ischium of 



the i^' pair of legs, are all distributed throughout the North Pacific either on the east or on 



the west side, except only Patidalopsis ampla Bate, which was taken by the "Challenger" off 



Monte Video, but afterwards proved to range also from Washington to Me.xico on the west 



coast of North America. Pantonms parvulus A. M.-Edw. is the only representative of a genus, 



which is characterized, like the genus Rhynchocitieies H. M.-Edw., by the rostrum being movably 



articulated with the carapace : this rare Crustacean is still only known from oft' the south coast 



of the United States. Except probably this remarkable genus Pantovius and except the genus 



Peripandalus, the preceding genera do not occur between the tropics, the six remaining, however, 



are all represented in the tropical seas. It appears superfluous to expatiate on the distribution 



of these genera, that are all represented in this collection, because in the general introduction 



to each genus the geographical range of their species will be fully elucidated. 



Very interesting are the catches made by the "Siboga" in this family, not only on 

 account of the discovery of three new species and two new varieties, all remarkable, but also 

 on account of the great number of specimens of some species, so that our knowledge of this 

 family has considerably increased. As the result of the investigations chiefly of the "Challenger" 

 and of the "Siboga", we know at present that the Indian Archipelago is inhabited by 10 species 

 and I variety of Heterocarpus A. M.-Edw., by 10 (or probably 12) species and 2 varieties of 

 Plesionika Bate, by 2 or 3 species of Parapandalus Borr. and by one species of each of the 

 three genera Dorodotes Bate, Chlorotocella Balss and Clilorotocus A. M.-Edw. 



Key to the genera of Pandalidae. 



^j Carpus of 2'"' pair of thoracic legs multiarticulate, the 

 number of articulations more than three. 

 (Jj Excepting a postrostral crest the carapace is smooth, 

 fj Rostrum immovable. 

 d^ Eyes large, much wider than the eyestalk. 

 e^ External maxillipeds with exopodite. 



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