249 Part III. — Tiventy-second Annual Report 



The fifth pair of thoracic feet are rather longer than broad, the 

 termiual portion being distinctly small and wider than the proximal 

 half; each foot carries three moderately long apical setae, as shown in 

 the drawing (fig. 17, pi. xiii.). 



The furcal joints, which are of moderate length, are each furnished 

 with three setae (fig. 19, pi. xiv.). 



Habitat.— Mauchrie Bay, Arran, Firth of Clyde, September 17, 1886. 

 St. Andrews Bay, August 7, and off St. Monans, Firth of Forth, 

 September 6, 1890. Dornoch Firth (Moray Firth district), July 30, 

 1895. Whitefarland Bay, Arran, Firth of Clyde, July 6, and between 

 Arran and the Ayrshire coast, November 9, 1899. All the specimens 

 obtained were females. 



Remarks. — I have adopted I. C. Thompson's name for this form in 

 preference to that of Dr. Giesbrecht, as I am convinced, after examining 

 a number of individuals and comparing them with the descriptions and 

 figures of Thompson and Bourne, that Thaumaleus rigidus (I. C. 

 Thompson) and T. clajparedii are identical. The antennules of the 

 female in both are short and stout, and although Thompson's figure 

 indicates a greater number of articulations than is observed in T. claparcdii, 

 this may be due perhaps to certain constrictions having been mistaken for 

 joints ; but what I rely on chiefly is the structure of the abdomen and the 

 form and armature of the fifth pair of thoracic legs of the female, which, 

 so far as they are represented by both Thompson's and Bourne's figures, 

 are practically the same as the similar parts of T. claparcdii represented 

 by the drawings of Dr. Giesbrecht. 



TJiaumaleus zetlandicus, T. Scott, sp. n PI. xiii., fig. 18, 19 ; pi. xiv., 

 fig. 20-22 j pi. xv., fig. 3, 4. 



Description of the Female. — Body moderately stout and elongated ; 

 length of the specimen represented by the drawing (fig. 18, pi. ii.), 4'8 mm. 

 (nearly -i- of an inch). The cephalothoracic segment is about one and a 

 half times the entire length of the remaining segments of the thorax and 

 abdomen. 



The abdomen is composed of three segments ; the first segment is 

 distinctly larger than the last segment of the thorax and about twice the 

 entire length of the next two abdominal segments ; these two segments are 

 sub-equal, but the second is slightly the longer of the two (fig. 22, pi. xiv.). 



The antennules, which are short and moderately stout, are composed of 

 four joints ; the first and third joints are smaller than the others, while 

 the end joint is about equal to the entire length of the other three 

 (fig. 20, pi. xiv.). 



The fifth pair of thoracic feet are short and broadly foliaceous and 

 terminate in two broad rounded sub-equal lobes, the outer one of which 

 is provided with three moderately long setae ; the inner lobes do not 

 appear to carry any setae (fig. 21, pi. xiv.). 



A male belonging apparently to the same species as the female 

 described above is considerably smaller than it, and the cephalothoracic 

 segment is only slightly longer than the combined lengths of the other 

 thoracic segments (fig. 19, pi. xiii.). The length of this male, which is 

 represented by the drawing just referred to, is 2*6 mm. (or nearly -^ of 

 an inch). The antennules are five-jointed and longer than those of the 

 female (fig. 3, pi. xv.) ; the abdomen appears to consist of four segments, 

 the first two are sub-equal and are each distinctly smaller than the last 

 segment of the thorax, while the last two are together only a little 

 longer than the preceding segment. The number of furcal hairs is the 

 same as in the female (fig. 2, pi. xv.). 



Habitat. — Lerwick Harbour, Shetland, October 15, 1901. 



