392 Recent Literature. [May, 



mences the publication of the results of the examination of a rich 

 collection of fishes made by the Marquis Giacomo Doria and Dr. 

 Odoardo Beccari during their residence at Sarawak. 



Eighteen species of Siluroids, two of them new to science, and 

 two others not before known to occur in Borneo are described ; 

 raising, with six species enumerated by E. Von Martens in the 

 Zoology of the Prussian Expedition to Eastern Asia, the total 

 number of known Bornean siluroids to fifty-eight. 



The writer remarks that he finds many new species in this col- 

 lection, and that this may be expected from the fact that, except 

 Bleeker, few naturalists have collected the fishes of the island. 



H. Schlegel, S. Miiller, and J. Richardson had noted only ten 

 Bornean species before the time of Bleeker, who, examining the 

 collections made by Dutch government officials, raised the num- 

 ber to three hundred and forty, all of which were from few locali- 



Since that date the only additions to our ichthyological knowl- 

 edge of Borneo have been the description by Dr. A. Giinther of 

 two species of Gobiidae, which formed part of the Doria collec- 

 tion, and the chapter by Martens on ninety-four species of fresh- 

 water fishes from the rivers Kapuas and Sambas. 



Mark's Maturation, Fecundation and Segmentation of 

 Limax. 1 — This work is very timely, and is valuable, both from the 

 original facts it contains regarding the intricate subject of the 

 preparation of the egg of the slug for fertilization, as well as the 

 latter process, and the mode of segmentation, which is of great 

 value from the detailed exposition for the English- reading student 

 of a department of embryology which has been mapped out 

 mainly by German embryologists. 



The author first gives us his own original observations, illus- 

 trated by five excellent double plates, and then presents us with a 

 lengthy discussion* and review of all the papers and works which 

 have been published on the earliest phases of embryonic develop- 

 ment above enumerated. 



In the third part, Dr. Mark presents theoretical considerations 

 and general conclusions regarding the promorphology of the 

 ovum, polar phenomena, asters, spiral asters, the nuclear spindle, 

 origin of nuclei, the germinative vesicle and polar globules. The 

 appearance of such a profound, critical summary of what is known 

 on these points, should give a stimulus to those studies in this 

 country. The treatment of the subject by the author is clear, 

 candid, and the matter well digested and elaborated. 



Gentry's Nests and Eggs. 2 — It is hard to say whether we look 

 upon these beautiful colored lithographs, representing the nests 



1 Bulletin of the. Mu ■<: f Comhtrat ,/,. t \ v ,U ll.irvnrd Coll <y, Vol VI, N<>. 

 E. L M\Rk. ( mil.-, L"', i i, ■ . isM."" ,Sv.., | 17; "-^ > ; '«-'-• 



