of the Fishery Board for Scotland. 259 



Herrmannella rostrata, Canu (1891) [ = Lichomolgus agilis, T. Scott 

 (1892). Firth of Forth.] 



The structure and armature of the inner branches of the fourth pair 

 in Herrmannella are somewhat similar to those of Sabelliphilus, but the 

 first two joints of the anterior antennae are cylindrical and not swollen as 

 in that genus. 



Modiolicola insignes, Aurivillius. (Firth of Forth.) 



This species of the Lichomolgidse somewhat resembles both Sabelliphilus 

 and Herrmannella in the structure and armature of the fourth pair of 

 feet. It also resembles Herrmannella in the form of the anterior 

 antennae, but it differs from Sabelliphilus in the first two joints of the 

 anterior antennae being cylindrical and not dilated; and it differs from 

 Herrmannella in the anterior foot-jaws (the external second-maxillae) 

 being furnished with only one internal smooth seta on the basal part of 

 the second joint; whereas in Herrmannella, there are two setae on the 

 inner part of the base of the second joint of the anterior foot-jaws, one 

 seta being comparatively short and smooth, and one elongate and denticu- 

 late. 



Lichomolgus arenicolus, Brady, is evidently not a true member of the 

 genus Lichomolgus. In this species both branches of the fourth pair are 

 three-jointed, and their armature is very similar to that of the second and 

 third pairs ; but it varies also in other structural details, and to such an 

 extent that it cannot satisfactorily be placed in any of the genera I have 

 referred to. The same may be said of an interesting species discovered 

 some time ago by I. C. Thompson of Liverpool, and described by him 

 under the name of Licliomolgus maximus ; the species was found living 

 as a mess-mate within the shell of the large scallop, Peeten maximus. 

 That this is not a true Licliomolgus, according to the definition of the 

 genus I have already referred to, will be at once apparent from the follow- 

 ing quotation from Mr Thomson's description of the species. He says : — 

 ' The first four pairs of swimming-feet have both branches three-jointed.' 



'It agrees with Licliomolgus agilis ' ( = Herrmannella rostrata, 



Canu) ' in having the inner branch of the fourth pair of swimming-feet 

 ' three-jointed.' It is evident from this description, and independent of 

 other structural differences, that Licliomolgus maximus is not, any more 

 than Licliomolgus arenicolus, a true member of that genus ; but the 

 question as to which genus they should be assigned, to secure for them a 

 satisfactory resting-place, is a matter requiring further study. It is quite 

 possible that their structural details may not meet the conditions of any 

 described genus. Lichomolgus maximus, however, appears to have a 

 closer affinity with Modiolicola Aurivillius, than with any of the other 

 genera referred to here. 



Pseudanthessius tliorellii (Brady and Robertson). 



1875. Licliomolgus tliorellii, Brady and Robertson (10), p. 197. 

 1880. Lichomolgus thorellii, Brady (8), vol. iii. p. 47, pi. 



lxxxviii. figs. 1-9. 

 1893. Lichomolgus thorellii, I. C. Thompson (33), p. 33, pi. xxv. 



fig. 2 c. 



Habitat. — Off St Monans. Scarce. 



This appears to be one of the rarer species of Licliomolgus. I find 

 comparatively few records of its occurrence in the British seas. Dr Brady 

 obtained it at one or two places off the Durham and Yorkshire Coasts. 

 Mr I. C. Thompson obtained it at Port Erin, Isle of Man ; Moray Firth 

 amongst Fillograna (A. S.) ; these, with the present record of its occurrence 

 in the Forth, are the only British records for this species known to me. 



