31 



1. A branchiostegal spine : last pair of thoracic legs do not reach 



the tip of the antennal scale: — 



i. Branchiostegal spine small, placed at the antero-inferior 



angle of the carapace ... ... ... P.fasurus. 



ii. Branchiostegal spine large, placed some way above and 



behind the antero-inferior angle of the carapace ... P. investigatori-: 



2. No branchiostegal spine : last pair of thoracic legs reach a good 



way beyond the tijj of the antennal scale ... ... P. longipes. 



II. Carapace without sutures : telson with 3 pairs of articulating marginal 



spines in addition to the fixed pair ... ... ... P. rectacutus. 



1. Parapeneps FissuRrs (Spence Bate). Plate V., fig. 16, I6a, b. 



Pena;us jissurus, Spence Bate, Challenger Macrnra, p. 26.3. pi, xxxvi., fig. 1, 1888; Borradaile, Stomatop. ami 

 Macrura of Willey's Exped., 1899, pp. 395, 40J. 



Glabrous, the integument firm but thin. 



The rostrum in the female reaches nearly to the tip of the antennular pe- 

 duncle, but in the male falls short of the middle of its second joint : it has a 

 faint double curve, and is armed dorsally with 6 teeth in addition to a remotely 

 isolated epigastric one : the post-rostral carina is very distinct and is continued 

 almost to the posterior border of the carapace. A small orbital tooth. Post- 

 antennular (antennal) spine strong, its buttress separated from the hepatic spine 

 by a deepish fossa, which is all that represents the cervical groove : post-anten- 

 nular sulcus rather shallow. A minute branchiostegal spine at the antero- 

 inferior angle of the carapace, produced upwards and backwards as a fine 

 sinuous ridge which ends below the strong hepatic spine, and represents the 

 boundary of the vanished anterior part of the cervical groove. 



A very fine suture extends longitudinally on each side, from the orbital 

 almost to the posterior border of the carapace. A similar suture extends trans- 

 versely across the branchiostegite near the level of the 2nd pair of chelipeds. 



The 4jth — 6th abdominal terga are sharply and thinly carinate in the middle 

 line, each carina ending acutely. The 5th abdominal somite is hardly two-thirds 

 the length of the 6th : the 6th is about as long as the telson : the telson is about 

 as long as the inner caudal swimmeret, and ends in an acicular spine, on either 

 side of which is a fixed marginal spinelet. 



The inner antennular flagellum, which is the longer, is from i^ to 1| 

 times the length of the peduncle. The eyes are large and surpass the antennu- 

 lar scale. 



The external maxillipeds reach into the distal third of the antennal scale : 

 the dactylus articulates end-on with the propodite. There is a spine on the 

 basis, and ischium, of the 1st pair of chelipeds only. No exopodites on any of 

 the thoracic legs. 



The andricum is symmetrical : it consists, in the adult, of two lobes finely 



