OF PLYMOUTH AND THE ENGLISH CHANNEL. 253 



portionally long ; a median group, where the chfetfe are by far the 

 most numerous, and are stout, the spinulose region being distinctly 

 shorter, and shortening as the chtetse pass to the ventral region, 

 where it is shortest. The shafts of the most ventral chaetee are 

 distinctly more slender, and form the third group, which is not always 

 so sharply defined as the others. 



The ventral cirrus is scarcely half the length of the neuropodium 

 measured from the point of insertion of the cirrus. 



With the doubtful exception of the first two feet, all the choetoe are 

 bifid at the extremity, the only difference being the depth of the cleft. 



The presence of chsetse in the notopodium is not a constant character. 

 No definite statement can be made either as to the number of the 

 segments or of the elytra, as these appear to be directly related to 

 the size of the animal. The largest specimen I have seen measures 

 8| inches in length with 67 elytra and 190 segments, and the smallest 

 is 1| inches long with 22 elytra. This last specimen, having been a 

 month or so in spirit, is almost colourless. Another specimen, 2 inches 

 long with 30 elytra, possesses the characteristic colour, but very feebly 

 developed. In these two cases the elytra completely cover the body. 

 A specimen, 5| inches long with 54 elytra and 150 segments, has 

 assumed the character and proportions described for the species. 

 Specimens of intermediate size are necessary to trace the change in 

 the proportions and colouration of the elytra. 



The segmental papillae are very prominent, more especially in the 

 posterior part of the body, and the anus is provided with two short cirri. 



The generic definition of Lepidasthenia given in the synopsis (p. 232) 

 is a verbatim copy of Malmgren's original. This author appears to 

 have had one or more specimens. Neither here nor in the original 

 description of Grube's Polynoe clcgans are any figures given, and 

 nothing is said as to its habits. A figure, however, is given by 

 Benham (3) in the Cambridge Natural History, and this unquestionably 

 proves that the Salcombe species is distinct. This species does not 

 accord with Malmgren's definition in the matter of the parapodia, but 

 the difference does not justify the creation of a new genus, and the 

 existing one must be amended in that particular. 



*Sthenelais boa, Johnston. 



This is a common species, and occurs between tidemarks on a more 

 or less sandy bottom, burrowing in the sand or under stones. It is also 

 tolerably frequent in dredgings, especially where the bottom consists of 

 stones and broken shells. 



Pruvot (29) records it from sandy beaches near low tide, and from 

 the zone of zostera banks. 



