Arenicola marina 95 



include representatives of two other species, namely, A. iJiiaiUa (from 

 Vancouver) and A. asdmilu var. ajinis (from An^ra Peciuena). 



Leach defined A. carhonaria as having "body, coal black." The 

 specimen, which was found near Leitli, is douljtless that in the 

 British Museum Collection labelled " Arenicola carhonaria. Black 

 liock, Frith of Forth. Mus. Leach." This is a very dark example 

 of ^. marina {cf. 1*1. I, Fig. 3). 



lianzani based his species Arenicola clavatns on three specimens 

 in the Museum of the L^niversity of Bologna.^ The jdace of origin of 

 the specimens '^ was unknown. Ranzani distinguished his new species 

 from A. piscatorniii, as described by I'allas and Cuvier, because the 

 anterior region was inflated and thicker than the middle region, the 

 tail was long and "articulated," and the gills black. The dilatation 

 of the anterior portion, due to the forward rush of the coelomic 

 fluid, and the articulation of the tail, caused by strong ccjntraction of 

 some of the circular muscles, are features of no s])eciiic value ; they 

 are seen in many specimens of A. marina which have been killed 

 quickly in alcohol. The specimen figured by llanzani was ab(jut 

 217 mm. long, so that, if from the Adriatic or any other European 

 source, it is certain to have been an example of A. marina, as the 

 other externally similar European species — A. yasilla — attains only 

 about half this length. A. clavatns may therefore be safely merged 

 with A. marina. 



The specimens'* on which (iirard founded the species A. 7iatalis 

 were shortly and iusutliciently described. Nevertheless, it is certain 

 that they were ordinary examples of A. marina. It is evident that 

 CJirard mistook the ventral for the dorsal surface, as he stated that 

 the dorsal region was marked by a conspicuous smooth line, dividing 

 on the cephalic region into right and left branches, which united 

 anteriorly. This smootli line, the dorsal position of which was given 

 as one of the specific characters, is, however, mid-ventral : it marks 

 the position of the nerve-cord, and is seen in all specimens of 

 A. marina. The other distinguishing features of .1. natalis — the 



' During a visit to that Museum tlie writer made inquiry for lianzani's 

 specimens, and careful, but unsuccessful, search was made for them ; they are 

 no longer preserved. 



- Oken (Isis (1817), 1452), but without stating his grounds, said that they 

 came from the Adriatic. The writer has examples of A. marina from Trieste, 

 wliich agree closely in size and appearance with those described by Ilanzani. 



■' The specimens have apparently not been preserved. The Curator of the 

 Boston Society of Natural History stated, in answer to the writer's inquiries, 

 that he had not been able to locate the type of A. natalis, and that there was 

 no record of its having been given to the Society. 



