110 BULLETIN : MUSEUM OF COMPAEATIVE ZOOLOGY. 



rami with rather feeble spines on the major part of the exterior margin ; the 

 inner ramus with some spines on the obliquely rounded terminal margin. 



Color. The dorsal surface is whitish, the eyes dark. 



Size. The single specimen, a female with marsupium, is 23.5 mm. long, and 

 10.7 mm. broad. 



Habitat. Station 3384 (Lat. 7° 31' 30" N., Long. 79° 14' W.), 458 fathoms, 

 1 specimen. 



Remarks. This species is closely allied to R. maculata Sch. & Meiu., but 

 it totally lacks the four large black spots ; furthermore, in the last named 

 species the uropods are a little shorter and broader, and the two rami of equal 

 bre;xdth, while the outer ramus is conspicuously shorter than the inner one ; 

 the three anterior pairs of legs are relatively shorter and more clumsy, etc. 



9. Irona foveolata, n. sp. 



Plate III. Fig. 4-4 6. 



Seven specimens, all females with marsupium, were secured. The species 

 certainly must be referred to the genus Irona Sch. & Mein., but as in my 

 opinion it would be of little value to work out a long and very detailed account, 

 I prefer to give a shorter description, especially pointing out the features by 

 which it is distinguished from the four species described by Schibdte and Mein- 

 ert in their monograph (Nat. Tidsskr., 3 R., Bd. XIV. pp. 383-395), and more 

 particularly from Irona melanosticta Sch. & Mein., to which it is rather closely 

 allied. As in adult females of other species belonging to Irona., Lironeca, etc., 

 the body is unsymmetrical and somewhat variable in shape, in some specimens 

 being contorted to the right, in others to the left side ; furthermore, the last 

 abdominal segment is sometimes as large as shown in the drawing (Fig. 4), 

 sometimes a little larger or smaller, in the smallest specimen even conspicu- 

 ously smaller. 



The body is about twice as long as broad, in the smallest specimen a little 

 shorter and broader, much depressed, but the dorsal surface of the thorax and 

 the median part of the five anterior abdominal segments yet more or less 

 but never strongly vaulted, while the lateral part of the abdominal segments 

 mentioned and the whole sixth abdominal segment are nearly or quite flat, but 

 sometimes obviously contorted. 



TJiorax. The epiraera of the second, third, and fourth thoracic segments are 

 very narrow, seen from above ; those of the fifth segment a little broader and 

 posteriorly more produced. The epimera of the sixth and especially of the 

 seventh segment are much broader and posteriorly much more produced than 

 the others, besides on each side rising considerably above the more lateral part 

 of the dorsal surface of the thorax, which is brought about by the curious fact 

 that these epimera are turned outwards and somewhat upwards. 



Abdomen. All the segments are very broad. The last segment either rather 

 thin and tolerably large, or mostly, as in Figure 4, thin and very large, and in 

 this instance almost membranous, so that the marginal part easily becomes 



