Mr H. Goodsir on fks Genus Cuma. 125 



arises from the extremity of the first segment, immediately internal to 

 the four last segments. The natatory or posterior division of this leg 

 is multlartlculatc ; tlic two first segments arc longest, being equal m 

 lencrth to tlie first segment of the anterior division ; the remaining seg- 

 ments are minute, about nine or ten in number, each of ^vhich gives 

 off a very long spinifcrous sctum, which is articulated at Its distal half.^ 

 The second thoracic leg of this species presents to us one of those 

 beautiful and delicate structures which it is impossible either to de- 

 scribe or delineate with even a remote degree of accuracy. The am- 

 bulatory division is very long and slender, six-jointed : the first jomt 

 is long and very much flattened, but tapers from the middle towards 

 its distol extremity, which is armed with a very long and pointed spine ; 

 the following joints arc all equal to one another in length, except the 

 last, which is minute. The natatory division of this leg is seven or 

 eight-jointed, and is equal in length to the first segment of the other 

 division. The five last segments arc all armed with long articulated 

 and spinifcrous setcc, which smaller spines arc again spinulose.t The 

 four following pairs of legs are simple, that is, they are merely ambu- 

 latory ; they are all six-jointed, and arc very spiny. The segments of 

 the body from which they arise are all ovoid, their dorsal edge being 

 sharp and pointed.^ 

 The abdominal portion of the body Is long and slender, seven-jointed 

 and monlliform ; the last joint is minute, and lies between the caudal 

 styles which arise from the extremity of the sixth segment ; these 

 styles are of no great length in this species ; they arc composed of 

 three parts ; each style consists of a long jointed peduncle, from the 

 distal extremity of which two biarticulated scales arise ; these scales 

 lie one above the other. The first segment of the peduncle is some- 

 what longer than the sixth abdominal segment ; the first segments of 

 the scales arc about half the length, and the last segment about one- 

 fourth the length of the peduncle ; the inner edge of the superior scales 

 is armed with a number of long, pointed, and articulated spines. The 

 spines which arise from the inner edge of the inferior scales arc more 

 numerous ; they arc all bent, their points being turned backwards ; the 

 convex or anterior edges of all these spines are very much serrated. || 

 I have named this species after M. Edwards, the founder of the genus, 

 and the leading crustaceologlst of the daj'. 



Cuma Audouinii. Ed\vards.§ 

 C. With the superior antennte very small ; with the first joint of the am- 

 bulatory division of the first pair of legs almost bent at right angles ; 

 the terminal joints oval, and the thumb-like process multiarticulatc. 

 Long four lines to five. Hab., Frith of Forth. 

 J)escH/j«on.— Under casual observation this species is very apt to be mis- 

 taken for that last described, but by careful examination the diflerence is 



• Plate II. Vi-. 10. t Plate II. Fist- 9. \ P^ate II. Fijr. 11, 12. 



11 Plate II. Fis- 13. S Plate II. Fig. 13. 



