270 BULLETIN OF THE 



Echinolampadae it can be traced only as a faint, indistinct narrow band. 

 The young of this Ecliinolampas resemble Caratomus to such an extent 

 (see the description of the young stages) that the larger specimens were 

 considered as living representatives of Caratomus. The series collected by 

 Mr. Pourtales in his second expedition shows conclusively that Echinolam- 

 pas passes at first through a stage strikingly similar to Echinoneus and 

 subsequently most closely allied to Caratomus. 



Note. — Uesmoulins has called attention to the fact that the Senegal 

 species should be named E. Laurillardi Des.ml., the name Richardii hav- 

 ing been applied by him to a fossil species from the tertiaries of Bordeaux, 

 from which it is different. 



From 35 to 1G0 fathoms. 



Rhyncholampas caribbsearum A. Ac, nov. gen. 



Syn. Cassidulus caribboearum Lam., An. s. Vert. 

 Cassidulus caribbasarum Lutk., Bid. 

 Nucleolites Richardii Duch., Antill. (non Desml.) 



Lamarck's genus Cassidulus, as established in 1801. contains in it two dis- 

 tinct types : Cassidulus lapis cancri and the species from the West Indies; 

 Cassidulus Marmimi has very justly been separated as a distinct genus, 

 Rhynchopygus by Desor, but this still leaves Cassidulus of Lamarck com- 

 posed of two types, for either of which the name Cassidulus might properly 

 be retained, but as Cassidulus is preoccupied among Mollusca, I would pro- 

 pose to retain temporarily Cassidulus for the fossil species allied to C. lapis 

 cancri, and leave to some palaeontologist the task of properly limiting that 

 genus, and separate from Cassidulus under the name of Rhyncholampas a 

 genus including Cassidulus caribbsearum and its West Coast representative, 

 which was originally named Pygorhynchus pacificus in theMuseum Bull. 

 No. 2. This view is the one Liitken adopted at first, but afterwards he has 

 referred these two species to Rhynchopygus, a change which docs not seem 

 judicious, and which his own excellent analysis and comparison of Cassidu- 

 lus and Rhynchopygus does not justify. Mr. Pourtales brought home 

 fragments of this species, showing that it must equal in size its pacific rep- 

 resentative. As it has been figured frequently, and described so well by 

 Liitken, T will only call attention to a few points of difference between the 

 East and West Coast species. The bare actinal band of the West India 

 species is deeply pitted with longitudinal round and elliptical pores, the 

 edges surmounted by minute tubercles, carrying extremely delicate spines, 

 resembling in every respect the s(jjructure of the microscopic spines of the 

 fascioles of the true Spatangoids. The spines in fascioles cannot be called 

 pedicellaria;, although it is the universal practice: they arc true spines, hav- 

 ing all t lie structure of embryonic spines, — in fact, true pedunculated pedi- 



