1908.] CAPE VERDE ISLANDS SPONGES. 781 



surface. These oxea reach a length of 2 mm., and their maximum 

 thickness when full grown is from 0*07 mm. to 0*08 mm. 



In the dermal cortex there are bundles of very small oxea, 

 many of which project from the surface at various angles. These 

 spicules (text-fig. 166, d) are more or less spindle-shaped and 

 are nearly or quite straight ; their diameter is 0*002 mm., and 

 they reach a maximum length of 0-25 mm. They occur almost 

 exclusively in the dermal cortex, but an occasional isolated spicule 

 is to be found in the parenchyma. 



The oscular fringe is composed of very long thin oxea. They 

 reach a length of from 1 mm. to 2 mm., and their maximum 

 diameter is 0'004 mm. 



In addition to the fringe there is, as usual, a short peristome 

 encircling each osculum. 



Colour (in alcohol) yellowish-white. 



This sjDonge bears a distinct resemblance to the well-known 

 Leucandra aspera (Schmidt). It differs from this species, how- 

 ever, by the presence of minute oxea in the dermal cortex. 

 Leihcandra gemmipara is also not unlike the above described 

 L. crosslandi^ but it is to be distinguished from the latter 

 (1) by the almost complete confinement of the small oxea to the 

 dermal cortex, (2) by having much more slender parenchymal 

 triradiates, and (3) by having smaller and different shaped dermal 

 trii-adiates. In addition to these and certain other minor differ- 

 ences, I may mention that there is an oscular fringe present on all 

 my specimens of L. gemmipara, but that this structure is not to 

 be found on any of the specimens of L. crosslandi. I hesitate, 

 however, to include this among the characters of specific value. 



Distribution. Cape Yerde Islands (Crossland Collection). 



Reference List of Literature. 



[1] Arnesen, E. — " Spongien fra den norske kryst. I. Calcarea. 



Systematisk katalog med bemerkninger og bestemmels- 



estabel." In Afhandlinger og Aarsberetning udgivne 



Bergens Museum. 1900. ISTo. 5. 

 [2] BowERBANK, J. S. — " Monograph of the British Spongiadse." 



1864-1882. 

 [3] Breitfuss, L. L. — " Kalkschwamme der Bremer-Expedition 



nach Ost-Spitzbergen im Jahre 1889." Zool. Anz. xix. 1 896. 

 [4] . " Die Kalkschwammfauna von Spitzbergen." Zool. 



Jahrbiicher, Syst. xi. 1898. 

 [5] . " Die Kalkschwamme des Weissen Meeres." Mem. 



Acad, des Sciences St. Petersbourg, ser. 8, vol. vi. 1898. 

 r6J . " Catalog der Calcarea der Zoologische Sammlung 



der koniglichen Museums fiir Katurkunde zu Berlin.'" 



Archiv f. Naturg. 1898. 

 [7] . " Die Arctische Kalkschwamme.'' Archiv f. Kature. 



1898. 

 [8] . " Die Kalkschwamme der Sammlung Plate." Zool. 



Jahrbiicher, Syst. 1897-1898. Supplement iv. 



