291 



Remarks. This new genus is based upon the form recorded by Th. Scott 

 under the name of Cletodes irrasa. A closer examination of this form has proved 

 it to differ in some points very materially from the other Cletodidae, and it should 

 thus more properly be regarded as the type of a particular genus. The general 

 outward appearance somewhat resembles that in the species of the succeeding 

 genus, Eurycletodes ; but the structure of the appendages is rather different. 

 Only a single species of this genus is as yet known. 



192. Mesocletodes irrasus (Scott). 



(PL CC). 



Cletodes irrasa, 1 ) Th. Scott, On some new and rare Crustacea from Scotland. Ann. Mag. Nat. 

 Hist., ser. 6, Vol. XIII, p. 141, PL VIII, figs. 1317. 



Specific Characters. Female. Body moderately slender and rather flex- 

 ible, with the segments well marked off from each other and edged behind with 

 dense rows of delicate spinules, giving it a somewhat hirsute appearance. Cephalic 

 segment sub-triangular in form, and scarcely longer than the 3 succeeding segments 

 combined, rostral projection very small, almost obsolete. Urosome (including the 

 caudal rami) fully as long as the anterior division, last segment large and thick, 

 with 2 interrupted transversal rows of spinules on each side, anal opercle broad, 

 semilunar and perfectly smooth. Caudal rami rather distant and narrow linear in 

 form, being about as long as the anal segment, and extending straight behind, each 

 with a whorl of 4 diverging setae in the middle, apical setae rather slender. An- 

 terior antennae nearly as long as the cephalic segment, and composed of 7 well 

 defined joints, clothed with strong, but not ciliated setae, 3 of them belonging to 

 the terminal part. Posterior antennae with the terminal joint scarcely dilated dis- 

 tally, apical spines comparatively short, outer ramus consisting of a narrow linear 

 joint carrying at the end 2 unequal setae. 1st pair of legs smaller than the suc- 

 ceeding ones, and having the usual spine inside the 2nd basal joint, outer ramus 

 about twice as long as the inner; that of the 3 succeeding pairs almost twice as 

 long as that of the 1st pair. Last pair of legs with the distal joint comparatively 

 small and very narrow, though widening slightly at the end, marginal setae rather 

 unequal and 5 in number, one of them issuing from the proximal part of the 

 outer edge, the others from the end; inner expansion of proximal joint confluent 

 with that of the other side, both forming together a broad plate slightly incised 

 in the middle, and carrying on each side of the incision 2 long ciliated setae, 

 outside which is another much shorter seta. Ovisac comparatively small. 



') Cletodes is apparently not a feminine, but a masculine name, like Laophontodes. 



