14 Bulletin Vanderhilt Marine Museum, Vol. V 



several localities, (Komai) ; Bonin Islands, (Odhner) ; Samboanga, 

 P. I., (Brooks) ; Sulu Sea, (Henderson) ; Pulo Edam, Java, (deMan) ; 

 British New Guinea, (Nobili) ; Ternate, (deMan); Owen Channel, 

 3 fm,, (Hansen) ; Caroline Islands, (Komai) ; Apia, Samoa, (Bige- 

 low) ; Dirk Hartog Islands, West Australia, (Hale) ; Sir C. Hardy's 

 Island, N. E. Australia, (Henderson) ; Rotuma, (Borradaile) ; Mau- 

 ritius: Grand Port, Chaland, Mapon, Port Louis, (Bouvier) ; Sey- 

 chelles, (Jurich; Borradaile); Cargados Carajos, Seychelles, (Bor- 

 radaile) ; British East Africa, (Borradaile) ; Zanzibar, (Lenz) ; Ibo 

 Archipelago, Portuguese East Africa. (Kemp) ; Palm Islands, Queens- 

 land, (Boone). 



Material examined : Two large specimens, taken on Falcon Island, 

 reef. Palm Islands, Queensland, Australia, October 7, 1931. One 

 young specimen, 20 mm. long, taken from coral, at Ingram Island, 

 Queensland, October 12, 1931. 



Technical description: This species differs from G. chiragra in 

 the following major essentials: 



(1) The rostrum is differently shaped, it being a subrectangular 

 plate with the outer angles rounded, the frontal margin straight, not 

 slightly concave, on either side of the median spine which is very 

 acuminate, about one and one-half times as long as the basal plate. 

 The dorsal process of the ophthalmic segment is composed of two 

 small plates, each of which is rounded anteriorly, these being much 

 narrower in G. glabrous than in G. chiragra, and much slenderer than 

 in G. demani. 



(2) In G. glabrous there is usually no small movable spine at the 

 base of the upper margin of the propodus of the raptorial claw. In 

 G. chiragra this spine is almost always present. 



(3) In glabrous there is a rather prominent pit present on the 

 lateral region of each of the third, fourth and fifth abdominal somites, 

 near the anterior margin. In G. chiragra this pit is vague or absent. 



(4) The telson of G. glabrous is perhaps the most conspicuous 

 distinctive character of the species. The sixth abdominal segment has 

 a distinct transverse flat carina which terminates on either side in a 

 sort of tubercle at the inner basal angle of the outermost longitudinal 

 triangulate tubercle. This carina is widest on the median region, its 

 posterior margin being convex. The six longitudinal tubercles of this 

 segment are in the form of elevated wide triangles, with the dorsal 

 surface of the inner four tubercles slightly rounded toward the mar- 

 gins, the apex an acute spine, projecting posteriorly above the telson. 



