404 Dr. J. E. Gray on the Arrangement of the Families 



One specimen only of what I believe to be a recent species of 

 Bellerophina has occurred to me, from the middle of the Indian 

 Ocean. From the general appearance of the shell, I should be 

 inclined to place the Bellerophontidse after the family Atlantidse, 

 among the Heteropods. 



Genus Litiopa, Rang. 



The species of Litiupa of Rang, or Bombyxinus of Belanger 

 and of Lesson^ are not well known. One is named saxicola, 

 another pelagica; but there is much confusion attending them. 

 About a dozen species have been described, but require to be 

 brought together and compared. This from the Indian Ocean 

 appears to be different from the others, and may be thus charac- 

 terized : — 



Litiopa venti'osa, A. Adams. 



L. testa ovato-conoidali, tenui, cornea, semipellucida, longitudinaliter 

 minutissime striata; spira elata, apice obtuse; anfractibus 4g, 

 convexis, ultimo ventricoso, basi producta ; apertura ovata ; labio 

 recto, antice truncato ; labro margine regulariter arcuate. 



Hab. Indian Ocean. 



There was no Sargassum in the sea whei'e this species was 

 taken in the towing-net. It is a somewhat inflated, thin, horny 

 shell, with the inner lip abruptly truncate, and the outer lip 

 continued beyond the truncature, so that the aperture cannot be 

 said to be truncate anteriorly. 



Shanghai, China, 

 May 3, 1861. 



XLI. — On the Arrangement of the Families and Genera o/Chloro- 

 spermous Algae, By Dr. John Edward Gray, F.R.S., 

 V.P.Z.S., F.L.S. &c. 



Having been recommended to change the course of my studies 

 for a time, I have returned to my " old love," and have been 

 devoting my vacation and my leisure time to the study of Algce 

 t.nd the reading of the various books and papers on the subject 

 which have come in my way. Thus, after an interval of forty 

 years, I have ventured to prepare a paper on systematic botany, 

 and to send to the ' Annals' some suggestions as to the arrange- 

 ment of the Chlorospermous Algae. 



I always look back with pleasure to the time that I spent 

 in collecting plants and in studying and teaching botany, and 

 especially to the period when I was occupied in preparing the 

 Bcieutific part of the ' Natural Arrangement of British Plants/ 



