14 ME. E. J. MIEES ON THE IDOTEID^. 



body. Eyes small, often indistinct or obsolete. Antennules about 

 reaching to the end of the antennal peduncle, with the basal 

 joint thickened and the rest slender and elongated. Antenuse 

 Avith the penultimate joint of the peduncle rather small and not 

 dilated; last joint longer than the preceding, flattened above, but 

 not dilated as in Idotea Sabini; flagellam about 8-14!-jointed. 

 Epimera of all the segments broad, with the postero-lateral angles 

 acute, and in the fourth to seventh segments considerably pro- 

 longed backward. Legs (in the adult) very robust ; the palmar or 

 penultimate joint of the first three pairs dilated, but narrowed at 

 the apex, where it is articulated with the slender dactylus ; the 

 four posterior pairs considerably elongated (the ]30sterior pair 

 reaching, when retracted, beyond the end of the postabdomen), 

 with the joints, except the dactylus, thickened, with more or less 

 hairy margins. Terminal valves of the operculum very small and 

 narrow ; in an adult example scarcely one fifth the length of the 

 preceding. Length of the largest specimen in the Museum about 

 3 inches (77 millim.), breadth rather more than I5 inch 

 (35 millim.). 



This species occurs in the Baltic, and not improbably through- 

 out the Arctic and circumpolar seas ; also in the depths o£ the 

 Swedish lakes (Prof. Loven). 



Specimens are in the collection of the British Museum from 

 the following localities: — An adult and four young examples 

 from the "Northern Seas " (O/r/ CoZZecif^ow, preserved dry) ; an 

 adult and younger example (dry) from the Cattegat (the Eev. 

 Prof, Haughton); two examples (dry) from the Baltic (Prof. 

 Loven) ; two small examples in imperfect condition from the 

 Banksian Collection, one of which bears the designation Saduria 

 entomon in, I believe. Dr. Leach's handwriting. A fine adult 

 example, sent by Mr. Lockington, under the name of " Idotcec/a 

 cdasTcensis" and labelled as coming from Behring's Straits, cannot 

 be distinguished specifically from the foregoing. It is probably 

 a male, but the second pair of postabdominal appendages are 

 without stylets. 



In the collection entrusted to me for examination by Prof. 

 Alph. Milne-Edwards, and containing the types of the Paris 

 Museum, is a male of rather small size from Sweden (Dr. 

 Malm), and labelled as inhabiting " les emisc douces." 



In none of the specimens I have examined is an incubatory 

 pouch developed. 



