410 Eev. 0. P. Cambridge on two 



in caves, where (the supposition is) the eyes have become 

 gradually and at length totally obsolete from ages on ages of 

 disuse. If in the present instance the eyes of this Ceylon 

 arachnid have vanished from a similar cause, the light having 

 been shut out merely by the interposition of decayed leaves, it 

 would seem to show, on the part of these creatures, a persistency 

 in keeping out of the light almost amounting to a quasi-suicidal 

 determination. 



Although undoubtedly a near ally to Thelyplionus, yet a 

 strong general resemblance to Solpuga may be traced in the 

 form and segmentation of the cephalothorax. The rough 

 sketches of the main features of form and structure, added to 

 the subjoined descriptions, will, it is hoped, give a better idea 

 of tlie peculiarities of tliese small but very interesting arachnids 

 than could be formed from description alone. 



Order Thelyphonidea. 



Fam. nov. Tartarides. 



Nearly allied to the family Thdyjilionides^ but diifering in 

 the general form, which is more elongate. The cephalothorax 

 also is divided into two parts or segments ; the first comprises 

 the caput and segments belonging to the first two pairs of legs, 

 the hinder part (much the smallest) comprises the segments 

 pertaining to the third and fourth pairs of legs ; but in neither 

 part are these segments indicated by any groove or indentation. 

 The abdomen is segmented, or rather covered both above and 

 below with articulated, corneous, transverse plates ; the upper 

 series is separated from the lower, being divided from it by a 

 horizontal narrow divisional line or space ; it terminates with 

 a short tail, varying in form in different species, and issuing 

 from the last of several small postabdominal rings or segments. 



Gen. nov. Nyctalops. 



GejpTialotliorax divided into two parts, oblong, tolerably 

 convex above ; the foremost part greatly the largest and of a 

 somewhat oblong form, broader before than behind, the fore 

 corners depressed and rounded ; the central part of the fore 

 margin is prolonged into a strongish pointed rostrum or beak, 

 the point of which is a little depressed ; the hinder part is 

 broadei than long, and appears to be simply an arched covering 

 to the sternal surface, upon which the two hinder pairs of legs 

 are articulated. 



Eyes none. 



Voices strong, much deeper than broad, of a flattened cylin- 

 drical form ; they project in the same plane as the cephalo- 



