ABT. 5 



PAKASITIC CRUSTACEA OF WEST INDIES BOSCH MA 



The internal anatomy of the species resembles strongly that of the 

 type species of the genus, Drepanorchis neglecta (see Boschma, 1927). 

 The closed end of the testes in D. occidentalis is found in the posterior 

 part of the visceral mass (nearer to the stalk than to the mantle 

 opening) ; in D. neglecta this part of the testes is situated at a com- 

 paratively greater distance from the stalk. The testes of D. occi- 

 dentalis have a fairly large size. (Fig. 2.) 



The colleteric glands occupy about the center of the lateral sur- 

 faces (in D. neglecta these organs are much nearer to the mantle 

 opening). The colleteric glands contain a comparatively small num- 

 ber of branched tubes. 



Fig. 1. — Two specimens op Dkepanoechis occidentalis. a, 



FROM MiTHEAX FORCEPS (A. MILNB-EDWAEDS) , THE SOKFACH 

 LYING AGAINST THE THORAX OF THE HOST, X 3%. h, THH 



SAME SPECIMB3N, THE SURFACE LYING AGAINST THE ABDOMEN OF 

 THE HOST, X 3%. C, FROM MACROCOELOMA CAMPTOCERUM 



(STIMPSON), the surface lying against THE THORAX OF 

 THE HOST, X 3. d, THE SAME SPECIMEN, THE SURFACE LYING 

 against THE ABDOMEN OF THE HOST, X 3. IN THESE FIG- 

 URES THE MANTLE OPENING IS FOUND IN THE UPPER PART, THH 

 STALK IN THE LOWER PART 



The typical characteristics of D. occidentalis are those of the ex- 

 ternal and internal cuticle of the mantle. The external cuticle is a 

 thin layer of chitin; its thickness does not exceed 10/t. It has a 

 smooth surface without any excrescences. Seen from above the sur- 

 face is divided into small areas which have a diameter of 10 to 15/4 

 and are surrounded by more or less meandering lines. (Fig. 3 a, h.) 



On the internal cuticle of the mantle a great number of retinacula 

 are found, more than in any other species of Sacculinid. (Fig. 3, 

 c-h.) The internal cuticle is divided into small areas of approxi- 

 mately 100/t diameter ; in detached pieces of this cuticle the marginal 

 parts of these areas are more or less wrinkled. Each of these small 



