102 



Regarding the geographical distribution of the Muriceidae collected by the Siboga Expedition, 

 it will be noted that but 29 of the 95 species are known to occur outside of the region explored 

 by the members of the party. 1 2 of these are confined to the East Indian Region, namely 

 Acanthogorgia spinosa, A. fiabellum, A. ceylonensis, M. gracilis, Versluysia ceyloncnsis, V. 

 ramosa, Bebryce indica, B. hicksoni, Echinomuricea coronalis, Villogorgia ruöra, Heterogorgia 

 ramosa and H. reticulata. 



The following species have been found in the Indian Ocean : — Muricella complanata, 

 M. perramosa, Echinogorgia furfuracea and E. pseudosassapo. 



Four species are known to inhabit the waters near Australia, i. e. Echinomuricea indo- 

 malaccensis, Echinogorgia furfuracea, E. pseudosassapo and Villogorgia intricata. Three species 

 are known to occur on the eastern shores of the Pacific: — Menacella reticulata, Echinogorgia 

 aurantiaca and Heterogorgia verrucosa. There are three species also from the West Indies, 

 namely: — Acanthogorgia armata, A. muricata and Villogorgia nigrescens. 



Two species, Muricella complanata and M. pcrramosa are known from the Japanese 

 coasts; two, Acanthogorgia ridleyi and A. laxa, from Patagonia ; one, Acanthogorgia ar/uala, 

 from the Atlantic coast of the United States; one, Placogorgia atlantica, from mid Atlantic; 

 one, Acanthogorgia armata, from the Hawaiian Islands in mid Pacific; and one, the same 

 species {Acanthogorgia armata) from the Cape of Good Hope. 



There is one species represented in the Siboga collection that was previously described, 

 but the locality in which it was found seems to be unknown. Reference is here made to 

 Menacella reticularis. 



It appears that Acanthogorgia armata has the widest geographical distribution of all 

 of the species in the collection, as well as a very extensive bathymetric range. The genus 

 Acanthogorgia seems to be very extensively dispersed over the sea bottom of the world. 

 Elasmogorgia filiformis has a very unusual known distribution, being found in the East Inches 

 and off the Californian coast. 



The writer does not feel justified in discussing at this time the general distribution of the 

 genera of the Muriceidae. Many of the earlier described species are of such uncertain identification 

 that little confidence can be feit in generalizations based in a considerable degree on these 

 questionable identifications ; and the types being in most cases inaccessible to the writer, he is 

 unable to ascertain points necessary to identification of many long known species. 



Again, there is so little uniformity among modern writers as to what constitutes a species, 

 especially among the lower metazoa, that conclusions regarding distribution are rendered still 

 more unsatisfactory. Conservative writers often lump together a number of forms, that would 

 be regarded as certainly distinct by others, in a single species. Thus the apparent geographical 

 and bathymetric range of such species is greatly extended; whereas other writers, with a 

 tendency to "hair-splitting" would divide the same forms into many species, thus restricting 

 the apparent range of the species discussed. 



Concerning another aspect of the question, the author has elsewhere said: ' 



1 Proceedings of the U. S. National Museum, vol. XXXIV, p. 546. 



