430 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



on this coast. Five species only are enumerated here, two of which are 

 also British, while Bate and Westwood enumerate twelve. A closer ex- 

 amination of the group may very likely add considerably to the present 

 list. 



The AselUdce and Munnopsidce, which Bate and Westwood would 

 unite, have seven marine si)ecies belouging to six genera in our list, and, 

 rejecting Limnoria, this number corresponds well with the British list 

 of four genera and six species ; one species, Jcvra alhifrons Leach, is 

 identical, as are three of the genera — Jccra, Jayiira, and Munna. The 

 more tj^pical forms of the Munnopsidce have not yet, as far as I am 

 aware, been recognized in British waters. 



The Idoteidw are more numerous on our coast and appear to be more 

 diversified than in Great Britain. I have regarded our eleven species 

 as belonging to five different genera, while Bate and Westwood include 

 the seven British species in a single genus. The most conservative 

 could hardly class our species in less than three genera to one English 

 genus, and, judging mostly from the figures and descriptions, I should 

 be inclined to reckon three, or at least two, English genera to five on 

 our coast in this family. One genus and species, Idotea irrorata Edw. 

 (Say), is identical. Of the ArctuHdm a single representative has only 

 recently been discovered within our limits, while three species, of the 

 same genus as ours, are mentioned by Bate and Westwood, and Steb- 

 bing has since added two more species. 



A single sijecies of Sphceroma is the only representative on our coast 

 of a family numbering no less than five genera and thirteen species in 

 Bate and Westwood's volume. If the last two of these species be united 

 as sexes of the same, and JDynamene rubra and viridis be also united, as 

 suggested by Stebbing,* there are still left eleven representatives of this 

 family in England to one on our coast. Our species is closely related 

 to the British Sphwroma serrattim Leach. Limnoria Ugnorum White 

 is the only known representative of its family on both coasts. 



The Cirolamdce and JEgidce, which are classed together under the lat- 

 ter name by most authors, have only four representatives in our limits, 

 belonging to three genera. Two of these genera are also found in Great 

 Britain, where they contain no less than seven species, one of which, 

 ^(/a psora Kroyer, is identical on the two coasts. Girolana truncata 

 Norman is not included in Bate and Westwood, but these authors men- 

 tion three other species belonging to as many genera in this grouj), 

 making five genera and ten species from Great Britain to only three 

 genera and four s]iecies in our waters. The Cymotholdw are represented 

 in oui- list by three species belonging to three genera, while Bate and 

 Westwood say of this family, ''No specimen has hitherto been satisfac- 

 torily determined as having been found in our own seas." The Kev. A. 

 M. jSTormau, however, in the Annals and Magazine of Natural History 

 for December, 18G8, p. •422, mentions and briefly describes Anilocra medi- 

 * Jour. Linn. Soc, Zool., vol. xii, p. 148, 1874. 



