NO. 1 DICKINSON : SPONGES OF GULF OF CALIFORNIA 3 



Since 1923 more than one hundred genera have been published. As 

 this paper deals largely with the Demospongia, Hentschel's system is not 

 practical. Earlier systems such as those of Minchin (1900) and Vosmaer 

 (1885) are not useful in present-day work, both because they are neces- 

 sarily incomplete and because they are not based on modern methods of 

 identification. 



A TAXONOMIC ANALYSIS OF THE SPONGES OF 

 THE GULF OF CALIFORNIA 



The taxonomic analysis developed in the following pages presents first 

 the order Keratosa, which is a complex and highly evolved group, and 

 proceeds to the order Carnosa, which is primitive. Keratosa contains the 

 type of the Phylum, as well as those sponges which are commercially 

 valuable. For this reason the order is much studied. It is of historical 

 interest because the keratose sponges are pictured on Grecian bas-reliefs, 

 perhaps the oldest known recording of marine invertebrates. The Carnosa 

 have evolved little beyond what is probably the most primitive Demo- 

 spongia. The group of Carnosa is small ; it contains no species of com- 

 mercial value and is little studied. Because it is primitive, it is more 

 closely related to the class Calcarea, which, since it is represented by few 

 specim.ens in the Hancock collection, is discussed last. 



Since many of the original descriptions of sponges need clarifying and 

 interpreting in terms of modern, uniform taxonomical usage, all species 

 studied, whether new or old, are described herein. 



Order KeRATOSA Bowerbank 



Family SpOngiidae Gray 



Genus HALME Lendenfeld 



Halme hancocki, new species 



Plates 1, 2, Figs. 1-4 



Diagnosis. — The specimen is a thin incrustation 8 by 5 by .5 cm and 

 is apparently a fragment of a much larger mass. In alcohol the color is 

 drab, both internally and externally. The color in life is not recorded. 

 The consistency is distinctly fleshy and very firm to the touch. Conules 

 are present on the surface, which is deeply pitted. Each depression is 2 to 

 3 mm in diameter and separated from the next only by a very thin wall. 

 The whole appearance is that of an empty honeycomb. The entire 

 specimen is exceptionally free of foreign material on the surface. The 

 underside is quite smooth, except for occasional depressions probably due 

 to irregularities in the surface of the coral on which the sponge grew. 



