54 report — 1865. 



taken this species when dredging in Plymouth Sound, but never so abun- 

 dantly as of late. 



We have previously observed the peculiar robust looking second pair of 

 pereiopoda, but it was not until recently we discovered that it had the pecu- 

 liar structural formation pecidiar to the genus Caradina, in which the pro- 

 podos articulates with the carpus, not at the centre, but at the infero-anterior 

 angle, and thus appears as a partially dislocated joint. 



There is a second specimen that appears to me to be specifically distinct 

 from the preceding ; it is more slender, and has the rostrum long and slight. 

 The teeth are two above, the one at the base flanked by a lateral tooth on 

 each side, and one near the apical extremity ; on the under side there is a 

 tooth immediately under the anterior upper tooth, and a second posterior to 

 it : to this species we provisionally give the name of Caradina tenuis. 



Among the sessile-eyed Crustacea we have added to our local fauna Mono- 

 culodes stimpsoni and Amphithoe albomaeulata ; of the latter we took but a 

 single specimen, and remarked the similitude of its colouring to that of half- 

 grown specimens of Amplntho'e ridjieaudata. 



Considerable numbers of Tanaia have been captured deeply inserted in the 

 crevices of the slate rocks of the coast, a habitat that is also favourable for 

 the residence of Anceus, a genus whose sexes have long been placed in sepa- 

 rate genera. These we have been enabled to work out with great care, a 

 circumstance that enables us to support some of the views of M. Hesse, and 

 unite the two supposed genera as the male and female of one. 



We have only to add the peculiar circumstance of our having captured 

 Chondrocantha zeia attached parasitically to a specimen of Synopta. 



Annelida. 

 Among the Annelida, Mr. J. Brooking Howe remarks that the following 

 have been made out, but we have many specimens as yet undetermined. 



Gen. Serpentaria. Gen. Psamathe. 



S. fusca. P. fusca. 



Gen. PontobdeUa. Gen. Ghjcera. 



P. muricata. Two species not yet determined. 



P. verrucata. Gen. Cirratulus. 

 Gen. Tomopteris. C. borealis. 



T. onisciformis. C. tentaculatus ? 



Gen. Aphrodita. Gen. Clutstopteris. 



A. aculeata. C. insignis. 



A. hystrix. Gen. Arenicola 

 Gen. Lepidonotns. A. piscatorum. 



L. squamatus. A. ecaudata. 



Gen. Siyalion. Gen. Terrebella. 



S. boa. Three species, which appear to 



Gen. Eunice. differ from any previously 



E. sanguinea. described as British. 



Gen. Northia. Gen. Pectinaria. 



N. tubicola. P. belgica. 



N. conchylega? Gen. Sabelht. 



Gen. Nereis. S. penicillus. 



N. brevimana? S. savignii. 



N. pelagica. Gen. Serpida. 

 Gen. Eeteronereis. S. vermicularis. 



H. longissima ? 



