MARINE ISOPODA OF NEW ENGLAND, ETC. 



371 



Spedmena examined. 



2054 



1224 

 2053 



2052 

 2049 

 2050 

 2051 



Locality. 



Florida 



Groat Egg Harbor, N.J. 



New Haven, Coun 



Savhi Eock, New Haven . 



Stony Creek, Conn 



Vinc'vard Sound, Mass . . . 



....do* 



....do 



Provincetown, Mass 



....do 



L. w. 

 L. w. 



L.w. 



L. w. 

 i 



Bottom. 



Rocky , 

 Rocky . 



Eel-grass. 



"WTion col- 

 lected. 



Received from— 



AprU, 1871 



, 1871 



, 1871 



, 1875 



Aug.— 1879 

 Aug.—, 1879 



Smithso n i a n 



Inst 



Smith (feVorrill 

 S.I. Smith.... 



TJ. S.EishCom, 



....do 



....do 



....do 



....do 



B o 



Bry. 

 Alo. 



Ale, 

 Ale. 

 Alo. 

 Alo. 

 Alo. 

 Alo. 

 Ale. 

 Alo. 

 Alo. 

 Alo. 



Vin.— LIMNORIID^. 



Body compressed ; antennulse and antennae short, subequal ; mandi- 

 bles palpigerous, formed for gnawing; feet not prehensile, all similar, 

 with short, robust dactyli ; epimera united with the thoracic segments ; 

 pleon of six distinct segments ; pleopods similar in form throughout j 

 uropods lateral, biramous. 



This family as constituted above contains the single genus Idmnoria 

 Leach, which appears also to contain but few, or perhaps a single, species* 

 of wide distribution. This genus was placed in the tribe AseUotes 

 liomopodes with the Asellidce by Edwards, without, however, having 

 examined the animals himself. He has been generally followed in this 

 arrangement by later authors. Previous authors had associated the 

 genus, as it appears to me more justly, with Splicer oma and the Gymo- 

 thoidce in the wide signification of the latter term. White, in his List 

 of British Crustacea, used the name Limnoriadce to include this genus 

 with the Asellidce. I have preferred to constitute a new family for the 

 genus, which has, however, evident relations with the Sphceromidce, and 

 perhaps should yet be united with that family. 



Under the circumstances family characters can scarcely be separated 

 with certainty from those of generic or even of specific value only, but 

 for the purpose of comparison with other famiUes certain important char- 

 acters may be here stated. The body is somewhat depressed dorsaUy, 

 but is also compressed at the sides, and when extended is subvermiform. 

 It is nearly capable of being roUed into a ball, as in the genus Sphmroma. 

 The head is of moderate size and strongly rounded above, as in Sphce- 

 romaj and the eyes are widely separated and on the sides of the head, a 

 condition not usual in the Asellidce. The autennulse are short and stout 

 and the basal segment is but little larger than the second ; the flageUum 



*It is i)erhaps hardly necessary to remark that L. xylophaga Hesse, Ann. Sci. nat., 

 tome X, p. 101, j)l. ix, 1868, is not an Isojiod. According to Prof. Smith it is Chelura 

 terebrans Phillipi, a boring amphipod often found associated with lAmnoria. See an 

 article by that author in the Proceedings of the U. S. National Museum, 1879, vol. ii, 

 pp. 232-235. 



