PANAMA SPONGES — DE LAUBENFELS 



453 



diameter. The oscules and pores are each minute and not readily- 

 made out. The root-Uke structures mentioned above are rendered 

 shaggy, being densely packed with spicules, and contain practically 

 no cavernous structures. The megascleres are spindle-shaped 

 strongyles, or strongyloxeas, commonlj^ ISju by 600^, occasionally 

 shghtly inequiended. Some, in fact, are almost styles. Spherasters 

 with very sharply pointed rays, total diameter about 65^, occur 

 abundantly in the whitish ectosomal layer and to a certain extent 

 also in the endosome. Both in the cortex and in the endosome occur 

 also a few asters with conspicuously hastate pointed ends to the rays, 

 total diameter 60/x, and comparatively abundant others, similar but 



Figure i3.—Taboga taboga, new genus and species: Spicules, X 666 (camera lucida). a, Common termina- 

 tion (of end toward ectosome) of the megasclere; 6, as above, but a less common sort; c, termination (away 

 from ectosome) of the megasclere; d, three views of the most distinctive sort of aster; e, three views of the 

 most common sort of aster; /, ectosomal spheraster; g, two views of the (uncommon) larger hastate rayed 

 asters. 



with very short rays, diameter 12)u. In the endosome occur only 

 long-rayed euasters (perhaps provided with a minute centrum), total 

 diameter 36/z to 60ju, the rays occasionally dichotomously or trichot- 

 omously branched at the end, and provided with a very few spines 

 lateraUy placed on them. 



One of the most remarkable characteristics of this unusual sponge 

 is the strength of its muscular (?) tissue. When a living specimen is cut 

 into deeply the cortex contracts so strongly that the endosome is 

 forced to protrude from the wound. The collector with his fingers 

 was unable to restrain this contraction and gives it as liis opinion that 

 the force was greater than that of the muscles that bend the fingers of 

 a person with ordinary strength. 



