HYALONEMA (HYALONEINIA) AGASSIZT. 



199 



of the distal rays, together with the spines, of the gastral cone-pinules, h, the 

 diameter of the niicrohexactines, i, the length of the large macramphidiscs, and 

 k, the length of the small micramphidiscs. The following table, arranged in 

 pairs, shows which of these qualities the forms A to F have in common. 



<a 



a 



o 



J3 



4656 (A) and 4651 (B) 

 " 4740 (C) 

 " " 3684 (A.A. 17) (D) 

 " " 4742 cake-sh. (E) 

 " 4742 pear-sh. (F) 



4651 (B) and 4740 (C) 



" 3684 (A.A. 17) (D) 

 " 4742 cake-sh. (E) 

 " 4742 pear-sh. (F) 



4740 (C) and 3684 (A.A. 17) (D) 

 " 4742 cake-sh. (E) 

 " 4742 pear-sh. (F) 



3684 (A.A. 17) (D) and 4742 cakc-sh. (E) 

 " 4742 pear-sh. (F) 



4742 cake-sh. (E) and 4742 pear-sh. (F) 



a e g h 

 c e f k 



g 



e g h i 



a b d e g h k 



b d e i 



b c d g k 



b c d e g h 



a c e g h 



abd 



a b d e 



e 



a b c d g 



c gi k 



c e g h 



These affinities are shown in Figure 8. 



Of the five stations where these sponges were trawled, two. Stations 4651 

 and 4656, lie near together ofT the Peruvian coast. The other three. Stations 

 4740, 4742, and 3684 (A.A. 17), are a considerable distance apart in the central 

 Pacific and are far from the two Peruvian stations. The degree of similarity 

 of the specimens separated as the six kinds of Hyalonema agassizi stands in no 

 relation to the distances of their localities from each other. Thus the cake- and 

 the pear-shaped specimens from Station 4742 agree only in respect to four of the 

 ten quaUties, and the pair from Stations 4651 and 4656, which lie very near 

 each other, also agree only in respect to four qualities. The pairs which agree 

 most are the pear-shaped specimens from Stations 4656 and 4742, which agree 

 as to seven quaUties, and the cake-shaped specimens from Stations 4651 and 

 4742, which agree in respect to six. The units of the pairs of stations from which 

 these come are very far apart. 



These and the other differences between the six kinds of Hyalonema agassizi 

 are not systematically important individually; I believe, however, that several 

 of them together demand recognition. Of the ten varying qualities here under 

 discussion, nine are different only in two pairs from Stations 4656, 3684 (A.A. 17), 

 and Stations 4740, 4742 pear-shaped. xAll the other pairs differ by from three 

 to seven of these qualities. Since the units of the two mentioned strongly diver- 

 gent pairs are connected in other ways, and since, as has been shown above, 

 there appears to be no correlation between the degree of difference and the 

 distance of the localities, I do not think that these differences warrant the 



