522 



NA TURE 



\_April I, 1884 



essentially isolated position, and as a group these maybe 

 divided into two orders : (l) Homoccela, and (2) Hetero- 

 ccfila ; the former with the single family Asconids (Leuco- 

 solenia, Bwbk.),the latterwith the three families Syconidas, 

 Leuconidie, and Teichonidse. The concluding portion of 

 the introductory chapter we quote as showing that, how- 

 ever destructive may be the author's criticism, he is not 

 unmindful of the merits of the author of " Die Kalk- 

 schwanime;" while mmy of Prof. Haeckel's statements 

 have thus proved to be founded on error, it must never 

 be forgotten that it was his Monograph that called forth 

 and facilitate i later investigations, and if we are forced 

 to agree to a certain extent with the judgment of M. 

 Barrois upon this great work, that " 1' imagination y a 

 trop souvent pris la place de I'observation scientifique et 

 froide," every one will also agree with another judgment 

 of the very same naturalist, that with the appearance of 

 Prof. Haeckel's Monograph "I'histoire des Eponges 

 entra dans une phase nouvelle." M. PoMjaeff's Report 

 is accompanied by nine plates, in which all the new forms 

 are figured. 



The Report on the Cirripedia is by Dr. P. P. C. Hoek. 

 Taking Darwin's Monograph as a basis of departure, the 

 authorgives us ( 1 ) a sketch of the development of our know- 

 ledge with regard to the number of the genera and species 

 known, their geographical and bathymetrical distribu- 

 tion ; (2) a summary of what has been added to our 

 knowledge of the anatomy, embryology, &c., of the group ; 

 and (3) a discussion of the different opinions published 

 with regard to the classification of the group, especially 

 since the discovery of the so-called Cirripedia Suctoria or 

 Rhizocephala. The first of these sketches is, from a 

 faunistic point of view, very interesting and instructive, 

 showing both how much and how little is known as to the 

 forms to be met with on our coasts or in our oceans ; and, 

 if properly studied, this section may give a very great 

 impetus to the local study of these forms. We read that 

 all " the Cirripedia of the Baltic belong to the genus 

 Balanus ;" but, if we are not mistaken, the extremely 

 curious species Anelasina squalicola has been found on 

 sharks in this sea, and specimens, we believe, from this 

 locality are to be found in the Berlin and Dublin 

 Museums. To the record given of species of fossil forms 

 described since the date of Darwin's Monograph we may 

 add one that has a peculiar interest being from the pen of 

 the late head of the civilian staff of the C/irt/Ztv/g^r Expe- 

 dition, describing Loricula macadaini from the Upper 

 Greensand of the County Antrim. 



Out of seventy-eight species of Cirripeds represented in 

 the Ciialkngcr collection only nineteen had been pre- 

 viously recorded, and fifty-nine are named and described 

 now for the first time. In 1854 Darwin gave the number 

 of known Cirripedes as 147, and since then only some 

 eighteen new species have been recorded. 



Of the thirty-four genera of Cirripedia at present known 

 the species of twenty-eight have never been observed at a 

 depth greater than 1 50 fathoms. Two have been found 

 from the shore to 400 fathoms (Alepas and Pcecilasma). 

 Balanus occurs from the shore down to 510 fathoms. 

 Dichelaspis ranges down to 1000 fathoms ; and finally 

 only two genera (Scalpellum and V'erruca) have been 

 observed at depths greater than 1000 fathoms. The 

 occurrence of these two latter genera in the greater 



depths of the ocean coincides in a striking manner with 

 their palxontological history, but Dr. Hocik has not been 

 able to identify any of the recent species with the extinct 

 forms described by Darwin, Bosquet, and Reuss. Of the 

 genus Scalpellum only eleven species were known up to 

 the cruise of the Challenger ; over forty species were 

 added to the list as the result of the cruise. The majority 

 of the species are inhabitants of deep water ; indeed 

 Sc;flpellum appears to be the only genus of the stalked 

 Cirripedia which is to be often met with at great depths. 

 It is also worthy of note that the observation of Darwin 

 made with regard to the number of specimens of Cirripeds 

 during the Cretaceous period may be made for the recent 

 species of Scalpellum: "The number of species is con- 



Scalpeltum damuinii. 



siderable, the individuals are rare." While the species 

 found during the Challenger cruise amounted to forty- 

 three, twenty-six of these are represented by a single 

 specimen only ; four are represented by two specimens ; 

 five by three ; two by four ; and only six species are 

 represented by more than four specimens. The study of 

 the complemental males found in some of the species of 

 Scalpellum has given some very interesting results, but 

 we are promised a more detailed treatment of the organ- 

 isation of these little creatures in a supplementary memoir, 

 whi;h will deal with the anatomy of the group, and which 

 will very shortly be published. In the account of S. 

 strocinii, Sars, we find the following: — 



" On opening a specimen of this species, dredged in 

 August 18S2 by H.M.S. Triton, it was found to contain 

 within the mantle cavity a few htrge embryos ; on micro- 

 scopic examination these were found to have passed 



