On two neio Genera of Starfishes. 89 



cylindricus, postice leviter ampliatus ; capite toto rugoso, para- 

 bolico, antice vix iuciso ; pronoto fortiter sat inoequaliter punc- 

 tate, postice medio Isevigato, lateribus regulariter arcuatis, basi 

 Itevissime trisinuato, augulis posticis rotundatis ; scutello laevi ; 

 elytris grosse baud profunda annulato-punctatis, punctis sub- 

 seriatis, lateribus Isevigatis, apicibus obsolete punctatis, stria 

 suturali Integra profunde impressa ; propygidii medio striis stri- 

 dulatoriis parum dense prajdito ; pygidii lateribus punctato- 

 rugosis ; mandibulis extus distincte trilobatus : 



J , capita breviter acute cornuto ; pronoto profunde longitudinaliter 

 excavato, lateribus utrinque biacuminatis ; pygidio politissimo : 



$ , paulo longiora, capite postice leviter angulatim carinato ; pygidii 

 medio subtiliter punctato. 



Long. 20-22-5 mm. ; lat. max. 11"5-12*5 mm. 



Hal. Astove T. 



A specimen of each sex was taken by Mr. P. R. Dupont 

 and presented by him to tlie Museum. It is a rather small 

 species of a dark reddish colour, and differs most markedly 

 from its allies by the obsolete hind angles of the prothorax. 

 The thoracic cavity of the male is rather narrow but deep, 

 and extends almost to the hind margin of the pronotum. 

 The punctures of the elytra are Large, but not deep, and not 

 distinctly arranged in rows. 



VII. — Tioo neio Genera of Starfishes. 

 By Walter K. Fisher, Stanford University, California. 



The new genera belong to the Benthopectinidse, their 

 position being somewhere between Benthopecten and Luidi- 

 aster [Acantharchaster) . Tiie type species were described 

 by me as AcantJiar chaster *, because the abactinal spino- 

 paxillpe, marginal plates, and adambulacial armature show a 

 great similarity to those of Acanthar chaster dawsoni. 



In his recent account of the Notomy ta f, Ludwig recognizes 

 eight genera, divided among two families, the CheirasteridaB 

 (corresponding to Verrill's Pontasterinse) and the Bentho- 

 pectinidEe. These two groups are equivalent to the Bentho- 

 pectinidse as employed by me in 1906$. The new genera 



* Zoologischer Anzeiger, Bd. xxxv., March 29, 1910, pp. 549-551. 

 t "Notomyota, eine ueue Orduung der Seesterne," Sitzungsb. k. preiiss. 

 Akad. d. Wiss. 1910, pp. 435-466. 



X U.S. Fish Comm. Bulletin for 1903, pt. iii. p. 1039. 



