Astacoidcs and Paiancplirops. 413 



the typical species P. planifrons^ wliicli is also the commonest 



spot'ies of the genus, the body is comparatively slender, the 

 anterior legs elongated, with the palm mure than twice as long 

 as broad, and clothed externally with longitudinally seriate 

 tubercles and spines ; moreover the antcnnni are inserted ex- 

 ternally to the antennules, and are furnished with a very large 

 basal scale, which is longer than the ])eduncle of the antennai. 

 It is true that in other species of both genera (as, f^r example, 

 Astaroides serratus^ Shaw, and A. Fntfi/>-/i/u'i\ (rray, from 

 Australia, and Paranejihrops zealandicus^ AViiite) the distinc- 

 tive characteristics are somewhat less strongly marked ; but, 

 so far as the materials in the collection of the British ]\Iuscum 

 atford means of comparison, I can sec no necessity for uniting 

 the genera. 



Professor Wood-Mason refers, I believe, to Paranephrops 

 zeahindicufi j^WntQ* J in speaking of '■^ Astacoides zealandlcus ;" 

 but this species is certainly distinct from P. sefosus, Huttonf. 

 In P. zealandicus^ of which the type specimens are in the 

 British-^Iuseum collection, the hands are clothed externally 

 with tufts of hair arransred in lonc-itudinal series, and are 

 armed with spines only upon the superior margins, and the 

 sides of the carapace are smooth. In P. setosus there are 

 spines an'anged seriately nj)on the external surface as well as 

 the upper margin of the hand, and the branchial and hepatic 

 regions of the carapace are armed with numerous unequal 

 conical spines. A specimen agreeing well with Hutton's 

 description is in the National collection. 



I may say in conclusion that a somewhat analogous mode 

 of attaclmient has been observed among the P]driophthalmata, 

 in the case of the young oi Arcturus^ by Sir J. G. Dalyell, 

 whose account is quoted by Messrs. Spence Bate and West- 

 wood in their '■ History of the British Sessile-eyed Crustacea,' 

 ii. p. 370. In this genus the young individuals affix themselves 

 in clusters to the antennaj of the mother, clasping the peduncles 

 of those organs with their prehensile three posterior pairs of 

 pereiopoda; and a specimen o{ A. Baffini actually exhibiting 

 this mode of attachment is preserved in the collection of the 

 British Museum. The young specimens are clustered chiefly 

 on the underside of the anteimaj, with the head pointing to- 

 ward the body of the parent. In this instance no specially 

 modified prehensile organ exists, nor, indeed, is such required. 



* Ai^tacm zcalandtcus, White, P, Z. S. 1847, p. 123, Aim. & Mag. Nat. 

 Hist. ser. 2, i. p. 225 (1848) ; Paraiiephn>p>< zeahmdicux, Mit.-rs, Zool. Erob. 

 & Terr., CriLst. p. 4, pi. ii. fig. 2 ( 1S74 ), Cat. Now-Zoal. Cruet, p. 73 (lJ^7(.i). 



+ .\iin. .'v: Mag. Nat. Hist. kt. 4, vol. .xii. p. 402(1873). 



