of the Fishery Board for Scotland. 227 



Attheyella propinqua sp. n. (provisional name), (PI. VII. figs. 1-11). 



Length, exclusive of caudal setae, '7 mm. (^-th of an inch), anterior 

 antennae rather longer and more slender than those of Attheyella eryptorum, 

 but resembling in this respect those of Attheyella spinosa ; the relative 

 length of the joints is also somewhat different, as shown by the formula — 



7 ' 7 ' 6 . • 7 ' 6 • 7 • 7 • 8. 



1 • 2 . • 3 ' 4 * 5 • e ' 7 ' 



The secondary branch of the posterior antennae is fairly well developed 

 and two-j Dinted ; the first joint bears one terminal seta, the second joint 

 bears two plumose terminal setae and a marginal one. The mandible, 

 which is elongate and of moderate breadth, has a small two-jointed palp 

 bearing a few setae (fig. 5). Posterior footjaws two-jointed and armed 

 with a slender terminal claw ; the first joint is provided, at the inner 

 distal angle, with a small spiniform seta. First pair of swimming feet 

 short, inner branch rather longer than the outer, and composed of two 

 nearly equal joints (fig. 7). The second, third, and fourth pairs similar to 

 those of Attheyella spinosa. Fifth pair, especially in the female, some- 

 what like those of Attheyella eryptorum ; those of the female rather 

 larger than in that species; the basal joint is broader and subquadrate, 

 and provided with shorter setae on the subtruncate end ; the second joint is 

 broadly subovate, the outer margin hearing a fringe of cilia in addition to the 

 five terminal and suhtermlnal setae. Fifth pair in the male smaller than in 

 the male of Attheyella eryptorum ; the extremity of the produced inner 

 part of the basal joint is subtruncate and provided with two small 

 plumose setae, second joint ovate with one moderately long plumose and 

 one short plain terminal setae; there are also two short plumose setae on 

 the inner margin, and three short setae on the outer margin. The second, 

 third, and fourth abdominal segments are each furnished with one concentric 

 fringe of short prickles close to the posterior margin, instead of two as in 

 Attheyella eryptorum. Seen from the side, the abdomen terminates 

 abruptly, with the fringed opercular plate projecting slightly upward 

 and backward. The male differs little from the female: the anterior 

 antennae are not so stout as in Attheyella eryptorum, and do not possess 

 the strongly developed lobe-like process, which is such a marked character 

 of the male antennae of Attheyella spinosa ; the third pair of swimming 

 feet are provided with shorter spines than the third pair of the male of 

 Attheyella eryptorum, but are otherwise somewhat similar to those of that 

 species ; caudal stylets very short. In bottom material both from the 

 head of Loch Morar and from Brinacory. 



The species now described is somewhat intermediate between Attheyella 

 spinosa and Attheyella eryptorum, but seems more closely allied to the 

 latter ; the three forms when placed together are readily distinguished from 

 eacli other by the form of the abdomen and stylets. In the species now 

 described, the abdomen, viewed laterally, is seen to end abruptly, with the 

 opercular plate showing as a distinct tooth like process ; and the abdominal 

 segments have only one fringe of setae. In Attheyella eryptorum, the 

 abdomen is more slender and ends much less abruptly than in the last 

 species, the opeicular plate is less prominent, and there are two rows of 

 setae on each of the abdominal segments ; moreover, the ovisac is somewhat 

 larger, so that the setae of the fifth feet do not reach to the end of it as in 

 Attheyella propinqua. In Attheyella spinosa the form of the stylets, which 

 are larger than in either of the other two species, are very characteristic, 

 as are al io the curled seta?, of the fifth feet. Dissection brings out other 

 more or less important differences as shown by the description and 

 figures. 



