conoiMiiTi).!-:. 209 



])od;i not hirgo, subeqiial, .subcholato ; second pair rather the 

 larger. I'ereiopoda short, robust ; posterior pair k)ngest, eoxai 

 small. Posterior pair of pleopoda very short, tenninating in a 

 single nimus formed like a double hook. Telson single ; lobe 

 crowned ^Wth several rows of sharp spines or teeth. 



Kroyer, in his figure of Sq^hontxcetKS typicus, has the posterior 

 pair of pleopoda double-branched, whereas, in the species that I have 

 had the opportunity of examining closely, there is only one ramus ; 

 but that consists of two hooks. These hooks arc not, as in Amphi- 

 thoe and CcnipHs, at the extremity of the ramus, but are themselves 

 the ramus, being united at the base. 



1. Siphoncecetus crassicomis. (Plate XLV. fig. 9.) B.M. 



Sipliono-cetus crassicomis, Spoicr Bate, Report Brit. Assoc. ISoo ; 

 Si/t2opsi3, Sf-c, Ann. Nat. Hist. Feb. 1857. 

 iniite, Hist. Brit. Crust, p. 197. 



Female. — Cephalon produced to a strong rostrum. Posterior divi- 

 sion of the pleon compressed beneath the anterior. Eyes round, 

 fixed on a lobe between the antenmc. Superior antennte about 

 one-fifth the length of the animal ; first joint of the peduncle as 

 long as the cephalon, very broad, armed above with a large strong 

 process which extends beyond the extremity of the second joint ; 

 second joint short ; third longer and more slender than the second ; 

 flagellum with two articuli, sparsely ciliated, first very long, second 

 rudimentary. Inferior antenna) reaching a little beyond the su- 

 perior, last two joints subequal ; flagellum having two articuli. 

 sparsely ciliated, first articulus as long as the last joint of the 

 peduncle, second small. Gnathopoda subequal, having the pro- 

 podos long-ovate, slightly tapering, palm not defined ; dactylos 

 serrated, impinging against the inferior margin. First two paii's 

 of pereiopoda subequal, having the basgs dilated ; propodos curved : 

 dactylos sharp and simply curved : third pair having each joint very 

 short and dilated ; meros and carpus posteriorly produced ; pro- 

 podos very stout, slightly curved ; dactylos doul)le-h()oked, pos- 

 teriorly directed : last two pairs gradually increasing in length, 

 and terminating in double-pointed dactyla posteriorly directed. 

 Penultimate pair of pleopoda short, scarcely reaching beyond the 

 peduncle of the preceding ; ultimate not reaching beyond the ex- 

 tremity of the antepenultimate, ha\nng the ramus developed into 

 a double-pointed hook. Telson single ; lobe crowned with small 

 teeth dii-ected upwards. 



Length -^ths of an inch 



Huh. Small tubes attached to Antennulana, coast of Northumber- 

 land {Mr. Alder). 



