264 Kepoet of the State Geologist. 



Anomocladina (1. c), Rauff refers it without hesitation to the 

 Tetracladina. 



Ulkich's observations and conclusions " respecting the minute 

 structure of the sponge agree very closely with those of both 

 Rauff and Hinde," but he follows the former in placing Hindia 

 with the Tetracladina. He describes the structure of the sponge 

 as follows : 



" The individual spicules have four rays or arms extending from 

 an inflated center. Three of the rays are nearly straight, of 

 nearly equal length, with their extremities expanded mostly in a 

 vertical direction. By their union a tripod-shaped body is formed, 

 from the upper surface of which the short fourth ray projects. 



" The connected structure of the skeleton is easily understood 

 after we have once determined the true form of the individual 

 spicules. In the first place the spicules form rather regular con- 

 centric layers, in which the individuals are arranged alternately 

 so that any one portion of each spicule is placed directly over or 

 beneath the corresponding portion of the spicules of the third, 

 fifth, seventh and ninth layers. The stumpy fourth ray is always 

 directed toward the exterior, while the three tripodal rays extend 

 toward the central nodes of three adjacent spicules of the layer 

 immediately beneath. The upper portions of the expanded 

 terminations in each case clasp about one-third of the fourth ray 

 of the latter, while the lower portion extends downward in a 

 recurving manner to the node or fourth ray of the spicule 

 directly beneath it." 



This description differs in two particulars from the structure as 

 worked out by Ra.uff^ and corroborated by IIinde. Ra^uff 

 showed that the union of the spicules does not take place by the 

 junction of the frilled ends of their rays with each other, as 

 stated by DTJ^^CAN, at first accepted by HiNDE,t and as the above 

 quotation certainly implies. Their mode of union is well shown 

 in figure 2, plate II. 



The tripodal rays are smooth on the inner and toothed on the 

 outer side.:j: The'union is effected in the following manner: The 



* H. Raufp, 1886. Sitzuogsber. Niederrh Gesellsch. zu Bonn. 



+ HiNDE, 1883. Cat Foss. Sponges of Brit. Mus,, p. 57. 



X — " und dass die Verbindung in die Weise gegchieht dass das ausgebreitete und gezahnelte 

 Kopfchen des einen A.rme8 gegen das in derselben Kanalflachen liegende convexe, ebenfalls 

 geziihneJte ^rmmittelstuck de-'jenigen seltlich benachbarten Elementes stosst, dessen Knoten- 

 punkt nicht mit den Ersten auf demselben Querschniit liegt, sondern gleichsam in einer halbe 

 Knctenenifernung (halbe M aschenhohle) dariiber oder darunter (Rauff, 1. c. p. 6). 



