LITERATURE. 297 



N- B. — Tu my regret 1 luive inadvertently laileil tu get access to the two following 

 works : 



W. Makshall. S|)ongiologische Beitrage. Festschr. z. "Usteii Wiederkelir (.1. Geburtst. 

 V. K. Leuckakt. Leipzig, 1892. 



C. Gravier. Sur line collection cV^ponges (Hesactinellides) dii Japon. Bull. Mus. 

 d'hi-^t. nat, Paris. T. V, no. 8, pp. 419-e22. 



The former paper, as known to me through an abstract, should toucli upon matters which 

 demand attention in relation to the morphology and physiology of the Hexactinellida. The 

 latter paper may jwssibly contain notes on some of the species described in this Contribution. 

 1 beg indulgence for any omissions in reference to these works. — I also very much regret 

 that I have not been able to benetit by Minciiin's ' The Porifcra ' (in Laxkestek's Treatise 

 on Zoology), the appearance of which work has become known to me too late to admit of 

 my securing a copy of it before finishing the printing oi this Contrilnition. 



