112 CHARLES D. SOAR AND W. WILLIAMSON ON 



length. The posterior margin varies from being rounded to 

 nearly straight, while the anterior margin stretches right across 

 from the anterior ends of the capsules. In the middle there is 

 a deep incision with a tapered process for muscle attachment 

 projecting well over it. On each side of the process there is a 

 moderate sized tubercle with a long bristle. The postero-lateral 

 region of the capsules bulges out very much, and gives the im- 

 pression of a deeper depression than usual in the outer edges. 



The palpi are about 1 mm. in length. The distal flexor surface 

 of the third segment is very much distended, and more densely 

 clothed with pectinate spines than E. extendens. Distributed 

 over the extensor surface numerous bristles are to be found. The 

 flexor surface of the fourth segment has two rows of spines with a 

 distal group of pectinate spines. The fifth segment at its distal 

 end is rather more tapered than E. extendens. 



Compared with the type, the capitulum is not so stout in its 

 general structure. Its processes are of a more slender form, with 

 the anterior pair decidedly longer, reaching nearly as far as the 

 distal extremity of the posterior pair. The anterior edge of the 

 maxillary plate lies well forward, with a more or less angular 

 indentation in the middle. Except along the posterior margin, 

 the maxillary plate is covered with pores. The ridge on the 

 pharynx is very strong and protrudes at the edges, so as to appear 

 like papillae. The metapharynx is large and extends beyond 

 the extremities of the posterior processes. The mouth area is 

 rather smaller than that of E. extendens. 



Only the male, which may attain a length of 3 "5 mm., appears 

 to be known. Its occurrence has been recorded for England and 

 Scotland, and on the Continent in Hungary and Austria, Germany, 

 Denmark and Norway, 



Eylais triarcuata Piers. (PI. 3, fig. 16). 

 1899. Piersig. Zool. Anz., vol, xxii. p. 66, fig, 7. 



The palpi and the intercapsular bridge in this form are rather 

 variable, and the opinion has even been expressed that it is only a 

 varietal form of E. extendens. 



The eye capsules are reniform, measuring about 0*27 mm, in 

 length. The anterior eyes have a short stalk, while the posterior 

 pair are pf the usual form. The length of the intercapsular 



