AMMOTHEIDAE ii7 



adults and young, and (2) the presence of an anterior and a posterior conical projection 

 on the first coxa of each walking leg. Also, in the males, the femoral cement-gland opens 

 at the apex of a high, conical projection, whereas, in the first group, it is situated on a low 

 blunt eminence. 



The specimens in the Terra Nova collection (Caiman, 191 5, p. 66), also from the 

 Ross Sea, agree very closely with the holotype ; in the male the femoral tubercle is high, 

 but more blunt and situated more proximally than is the acutely conical tubercle in 

 the males of our second group (cf. Fig. 64 a and b). 



It is doubtful if these forms all belong to one variable species ; the walking legs show 

 considerable differences (Figs. 63 and 64). The main differences described above may 

 be represented briefly as follows: 

 Group I. Projections on mid-dorsal surface of trunk present; no anterior projection on first 

 coxa of first leg. 

 A. Projections on trunk low, rather robust, conical tubercles. 



1 . Two projections on first coxa of legs 2-4 ; femoral gland in male opens at the 

 apex of a high, wide, blunt cone (Fig. 64 a) 



Holotype and Terra Nova specimens 



2. One projection on first coxa of all the legs [a small posterior one may also be 

 present on the third leg] ; femoral gland in male opens at apex of a very 

 low, blunt eminence (Fig. 63 b) Discovery, St. WS 228 



B. Projections on trunk high, slender, spinose; two high projections on first coxa 

 of legs 2-4; femoral gland in male opens at apex of a low, blunt, rounded 



eminence (Fig. 64 f) Discovery, St. 53, St. WS 33 



Group II. Projections on mid-dorsal surface of trunk absent; anterior and posterior projections 

 on the first coxa of each leg; femoral gland in male opens at apex of a high, narrow 

 cone (Fig. 646) Discovery— all the remaining stations 



The material described by Bouvier (1913, p. H?)- to judge from the arrangement of 

 the coxal processes, is similar to that from WS 228. The low femoral tubercles in the 

 male would be much more easily overlooked than the high conical ones, which are very 

 striking even in immature specimens (see Caiman, 1915, p. 67). 



The males, in many cases, appear to be quite adult, although the genital openings have 

 not been observed with certainty, in several instances there seemed to be a small 

 opening on the second coxa of the last leg. 



Distribution. Probably circumpolar; recorded from the Ross Sea area, Graham 

 Land region, South Georgia and the Magellan district. 



Genus Tanystylum, Miers 

 A number of previous workers (e.g. Norman and Loman) regard the genus Chtenia, 

 Dohrn, as a synonym of Tanystylum, Miers. Bouvier (191 3- P- 45) retains Chtema, at 

 least provisionally, as distinct from Tanystylum, the former having only four, mstead 

 of six or seven segments in the palp. Bouvier, however, includes T. hoekianum, Schimk., 

 in the genus Clotenia, although the palp is described and figured with six segments. 



